/**
 *  date : 2023-04-07 23:16:20
 */

#define NDEBUG
using namespace std;

// intrinstic
#include <immintrin.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cfenv>
#include <cfloat>
#include <chrono>
#include <cinttypes>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdarg>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <fstream>
#include <functional>
#include <initializer_list>
#include <iomanip>
#include <ios>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <streambuf>
#include <string>
#include <tuple>
#include <type_traits>
#include <typeinfo>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

// utility
namespace Nyaan {
using ll = long long;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128_t;
using u128 = __uint128_t;

template <typename T>
using V = vector<T>;
template <typename T>
using VV = vector<vector<T>>;
using vi = vector<int>;
using vl = vector<long long>;
using vd = V<double>;
using vs = V<string>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<long long>>;

template <typename T, typename U>
struct P : pair<T, U> {
  template <typename... Args>
  P(Args... args) : pair<T, U>(args...) {}

  using pair<T, U>::first;
  using pair<T, U>::second;

  P &operator+=(const P &r) {
    first += r.first;
    second += r.second;
    return *this;
  }
  P &operator-=(const P &r) {
    first -= r.first;
    second -= r.second;
    return *this;
  }
  P &operator*=(const P &r) {
    first *= r.first;
    second *= r.second;
    return *this;
  }
  template <typename S>
  P &operator*=(const S &r) {
    first *= r, second *= r;
    return *this;
  }
  P operator+(const P &r) const { return P(*this) += r; }
  P operator-(const P &r) const { return P(*this) -= r; }
  P operator*(const P &r) const { return P(*this) *= r; }
  template <typename S>
  P operator*(const S &r) const {
    return P(*this) *= r;
  }
  P operator-() const { return P{-first, -second}; }
};

using pl = P<ll, ll>;
using pi = P<int, int>;
using vp = V<pl>;

constexpr int inf = 1001001001;
constexpr long long infLL = 4004004004004004004LL;

template <typename T>
int sz(const T &t) {
  return t.size();
}

template <typename T, typename U>
inline bool amin(T &x, U y) {
  return (y < x) ? (x = y, true) : false;
}
template <typename T, typename U>
inline bool amax(T &x, U y) {
  return (x < y) ? (x = y, true) : false;
}

template <typename T>
inline T Max(const vector<T> &v) {
  return *max_element(begin(v), end(v));
}
template <typename T>
inline T Min(const vector<T> &v) {
  return *min_element(begin(v), end(v));
}
template <typename T>
inline long long Sum(const vector<T> &v) {
  return accumulate(begin(v), end(v), 0LL);
}

template <typename T>
int lb(const vector<T> &v, const T &a) {
  return lower_bound(begin(v), end(v), a) - begin(v);
}
template <typename T>
int ub(const vector<T> &v, const T &a) {
  return upper_bound(begin(v), end(v), a) - begin(v);
}

constexpr long long TEN(int n) {
  long long ret = 1, x = 10;
  for (; n; x *= x, n >>= 1) ret *= (n & 1 ? x : 1);
  return ret;
}

template <typename T, typename U>
pair<T, U> mkp(const T &t, const U &u) {
  return make_pair(t, u);
}

template <typename T>
vector<T> mkrui(const vector<T> &v, bool rev = false) {
  vector<T> ret(v.size() + 1);
  if (rev) {
    for (int i = int(v.size()) - 1; i >= 0; i--) ret[i] = v[i] + ret[i + 1];
  } else {
    for (int i = 0; i < int(v.size()); i++) ret[i + 1] = ret[i] + v[i];
  }
  return ret;
};

template <typename T>
vector<T> mkuni(const vector<T> &v) {
  vector<T> ret(v);
  sort(ret.begin(), ret.end());
  ret.erase(unique(ret.begin(), ret.end()), ret.end());
  return ret;
}

template <typename F>
vector<int> mkord(int N,F f) {
  vector<int> ord(N);
  iota(begin(ord), end(ord), 0);
  sort(begin(ord), end(ord), f);
  return ord;
}

template <typename T>
vector<int> mkinv(vector<T> &v) {
  int max_val = *max_element(begin(v), end(v));
  vector<int> inv(max_val + 1, -1);
  for (int i = 0; i < (int)v.size(); i++) inv[v[i]] = i;
  return inv;
}

vector<int> mkiota(int n) {
  vector<int> ret(n);
  iota(begin(ret), end(ret), 0);
  return ret;
}

template <typename T>
T mkrev(const T &v) {
  T w{v};
  reverse(begin(w), end(w));
  return w;
}

template <typename T>
bool nxp(vector<T> &v) {
  return next_permutation(begin(v), end(v));
}

template <typename T>
using minpq = priority_queue<T, vector<T>, greater<T>>;

}  // namespace Nyaan

// bit operation
namespace Nyaan {
__attribute__((target("popcnt"))) inline int popcnt(const u64 &a) {
  return _mm_popcnt_u64(a);
}
inline int lsb(const u64 &a) { return a ? __builtin_ctzll(a) : 64; }
inline int ctz(const u64 &a) { return a ? __builtin_ctzll(a) : 64; }
inline int msb(const u64 &a) { return a ? 63 - __builtin_clzll(a) : -1; }
template <typename T>
inline int gbit(const T &a, int i) {
  return (a >> i) & 1;
}
template <typename T>
inline void sbit(T &a, int i, bool b) {
  if (gbit(a, i) != b) a ^= T(1) << i;
}
constexpr long long PW(int n) { return 1LL << n; }
constexpr long long MSK(int n) { return (1LL << n) - 1; }
}  // namespace Nyaan

// inout
namespace Nyaan {

template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << p.first << " " << p.second;
  return os;
}
template <typename T, typename U>
istream &operator>>(istream &is, pair<T, U> &p) {
  is >> p.first >> p.second;
  return is;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  int s = (int)v.size();
  for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i];
  return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v) {
  for (auto &x : v) is >> x;
  return is;
}

istream &operator>>(istream &is, __int128_t &x) {
  string S;
  is >> S;
  x = 0;
  int flag = 0;
  for (auto &c : S) {
    if (c == '-') {
      flag = true;
      continue;
    }
    x *= 10;
    x += c - '0';
  }
  if (flag) x = -x;
  return is;
}

istream &operator>>(istream &is, __uint128_t &x) {
  string S;
  is >> S;
  x = 0;
  for (auto &c : S) {
    x *= 10;
    x += c - '0';
  }
  return is;
}

ostream &operator<<(ostream &os, __int128_t x) {
  if (x == 0) return os << 0;
  if (x < 0) os << '-', x = -x;
  string S;
  while (x) S.push_back('0' + x % 10), x /= 10;
  reverse(begin(S), end(S));
  return os << S;
}
ostream &operator<<(ostream &os, __uint128_t x) {
  if (x == 0) return os << 0;
  string S;
  while (x) S.push_back('0' + x % 10), x /= 10;
  reverse(begin(S), end(S));
  return os << S;
}

void in() {}
template <typename T, class... U>
void in(T &t, U &...u) {
  cin >> t;
  in(u...);
}

void out() { cout << "\n"; }
template <typename T, class... U, char sep = ' '>
void out(const T &t, const U &...u) {
  cout << t;
  if (sizeof...(u)) cout << sep;
  out(u...);
}

struct IoSetupNya {
  IoSetupNya() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    cerr << fixed << setprecision(7);
  }
} iosetupnya;

}  // namespace Nyaan

// debug

#ifdef NyaanDebug
#define trc(...) (void(0))
#else
#define trc(...) (void(0))
#endif

#ifdef NyaanLocal
#define trc2(...) (void(0))
#else
#define trc2(...) (void(0))
#endif

// macro
#define each(x, v) for (auto&& x : v)
#define each2(x, y, v) for (auto&& [x, y] : v)
#define all(v) (v).begin(), (v).end()
#define rep(i, N) for (long long i = 0; i < (long long)(N); i++)
#define repr(i, N) for (long long i = (long long)(N)-1; i >= 0; i--)
#define rep1(i, N) for (long long i = 1; i <= (long long)(N); i++)
#define repr1(i, N) for (long long i = (N); (long long)(i) > 0; i--)
#define reg(i, a, b) for (long long i = (a); i < (b); i++)
#define regr(i, a, b) for (long long i = (b)-1; i >= (a); i--)
#define fi first
#define se second
#define ini(...)   \
  int __VA_ARGS__; \
  in(__VA_ARGS__)
#define inl(...)         \
  long long __VA_ARGS__; \
  in(__VA_ARGS__)
#define ins(...)      \
  string __VA_ARGS__; \
  in(__VA_ARGS__)
#define in2(s, t)                           \
  for (int i = 0; i < (int)s.size(); i++) { \
    in(s[i], t[i]);                         \
  }
#define in3(s, t, u)                        \
  for (int i = 0; i < (int)s.size(); i++) { \
    in(s[i], t[i], u[i]);                   \
  }
#define in4(s, t, u, v)                     \
  for (int i = 0; i < (int)s.size(); i++) { \
    in(s[i], t[i], u[i], v[i]);             \
  }
#define die(...)             \
  do {                       \
    Nyaan::out(__VA_ARGS__); \
    return;                  \
  } while (0)

namespace Nyaan {
void solve();
}
int main() { Nyaan::solve(); }

//

struct Rational {
  using R = Rational;
  using i128 = __int128_t;
  using i64 = long long;
  using u64 = unsigned long long;
  long long x, y;
  Rational() : x(0), y(1) {}
  Rational(long long _x, long long _y = 1) : x(_x), y(_y) {
    assert(y != 0);
    if (_y != 1) {
      long long g = gcd(x, y);
      if (g != 0) x /= g, y /= g;
      if (y < 0) x = -x, y = -y;
    }
  }

  u64 gcd(i64 A, i64 B) {
    u64 a = A >= 0 ? A : -A;
    u64 b = B >= 0 ? B : -B;
    if (a == 0 || b == 0) return a + b;
    int n = __builtin_ctzll(a);
    int m = __builtin_ctzll(b);
    a >>= n;
    b >>= m;
    while (a != b) {
      int d = __builtin_ctzll(a - b);
      bool f = a > b;
      u64 c = f ? a : b;
      b = f ? b : a;
      a = (c - b) >> d;
    }
    return a << min(n, m);
  }

  friend R operator+(const R& l, const R& r) {
    return R(l.x * r.y + l.y * r.x, l.y * r.y);
  }
  friend R operator-(const R& l, const R& r) {
    return R(l.x * r.y - l.y * r.x, l.y * r.y);
  }
  friend R operator*(const R& l, const R& r) { return R(l.x * r.x, l.y * r.y); }
  friend R operator/(const R& l, const R& r) {
    assert(r.x != 0);
    return R(l.x * r.y, l.y * r.x);
  }
  R& operator+=(const R& r) { return (*this) = (*this) + r; }
  R& operator-=(const R& r) { return (*this) = (*this) - r; }
  R& operator*=(const R& r) { return (*this) = (*this) * r; }
  R& operator/=(const R& r) { return (*this) = (*this) / r; }
  R operator-() const {
    R r;
    r.x = -x, r.y = y;
    return r;
  }
  R inverse() const {
    assert(x != 0);
    R r;
    r.x = y, r.y = x;
    if (x < 0) r.x = -r.x, r.y = -r.y;
    return r;
  }
  R pow(long long p) const {
    R res(1), base(*this);
    while (p) {
      if (p & 1) res *= base;
      base *= base;
      p >>= 1;
    }
    return res;
  }

  friend bool operator==(const R& l, const R& r) {
    return l.x == r.x && l.y == r.y;
  };
  friend bool operator!=(const R& l, const R& r) {
    return l.x != r.x || l.y != r.y;
  };
  friend bool operator<(const R& l, const R& r) {
    return i128(l.x) * r.y < i128(l.y) * r.x;
  };
  friend bool operator<=(const R& l, const R& r) { return l < r || l == r; }
  friend bool operator>(const R& l, const R& r) {
    return i128(l.x) * r.y > i128(l.y) * r.x;
  };
  friend bool operator>=(const R& l, const R& r) { return l > r || l == r; }
  friend ostream& operator<<(ostream& os, const R& r) {
    os << r.x;
    if (r.x != 0 && r.y != 1) os << "/" << r.y;
    return os;
  }

  long long toMint(long long mod) {
    assert(mod != 0);
    i64 a = y, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return i128((u % mod + mod) % mod) * x % mod;
  }
};

template <typename R = Rational>
struct Binomial {
  vector<R> fc;
  Binomial(int = 0) { fc.emplace_back(1); }
  void extend() {
    int n = fc.size();
    R nxt = fc.back() * n;
    fc.push_back(nxt);
  }
  R fac(int n) {
    while ((int)fc.size() <= n) extend();
    return fc[n];
  }
  R finv(int n) { return fac(n).inverse(); }
  R inv(int n) { return R{1, max(n, 1)}; }
  R C(int n, int r) {
    if (n < 0 or r < 0 or n < r) return R{0};
    return fac(n) * finv(n - r) * finv(r);
  }
  R operator()(int n, int r) { return C(n, r); }
  template <typename I>
  R multinomial(const vector<I>& r) {
    static_assert(is_integral<I>::value == true);
    int n = 0;
    for (auto& x : r) {
      if (x < 0) return R{0};
      n += x;
    }
    R res = fac(n);
    for (auto& x : r) res *= finv(x);
    return res;
  }

  template <typename I>
  R operator()(const vector<I>& r) {
    return multinomial(r);
  }
};



// Prime Sieve {2, 3, 5, 7, 11, 13, 17, ...}
vector<int> prime_enumerate(int N) {
  vector<bool> sieve(N / 3 + 1, 1);
  for (int p = 5, d = 4, i = 1, sqn = sqrt(N); p <= sqn; p += d = 6 - d, i++) {
    if (!sieve[i]) continue;
    for (int q = p * p / 3, r = d * p / 3 + (d * p % 3 == 2), s = 2 * p,
             qe = sieve.size();
         q < qe; q += r = s - r)
      sieve[q] = 0;
  }
  vector<int> ret{2, 3};
  for (int p = 5, d = 4, i = 1; p <= N; p += d = 6 - d, i++)
    if (sieve[i]) ret.push_back(p);
  while (!ret.empty() && ret.back() > N) ret.pop_back();
  return ret;
}

struct divisor_transform {
  template <typename T>
  static void zeta_transform(vector<T> &a) {
    int N = a.size() - 1;
    auto sieve = prime_enumerate(N);
    for (auto &p : sieve)
      for (int k = 1; k * p <= N; ++k) a[k * p] += a[k];
  }
  template <typename T>
  static void mobius_transform(T &a) {
    int N = a.size() - 1;
    auto sieve = prime_enumerate(N);
    for (auto &p : sieve)
      for (int k = N / p; k > 0; --k) a[k * p] -= a[k];
  }

  template <typename I, typename T>
  static void zeta_transform(map<I, T> &a) {
    for (auto p = rbegin(a); p != rend(a); p++)
      for (auto &x : a) {
        if (p->first == x.first) break;
        if (p->first % x.first == 0) p->second += x.second;
      }
  }
  template <typename I, typename T>
  static void mobius_transform(map<I, T> &a) {
    for (auto &x : a) {
      for (auto p = rbegin(a); p != rend(a); p++) {
        if (x.first == p->first) break;
        if (p->first % x.first == 0) p->second -= x.second;
      }
    }
  }
};

struct multiple_transform {
  template <typename T>
  static void zeta_transform(vector<T> &a) {
    int N = a.size() - 1;
    auto sieve = prime_enumerate(N);
    for (auto &p : sieve)
      for (int k = N / p; k > 0; --k) a[k] += a[k * p];
  }
  template <typename T>
  static void mobius_transform(vector<T> &a) {
    int N = a.size() - 1;
    auto sieve = prime_enumerate(N);
    for (auto &p : sieve)
      for (int k = 1; k * p <= N; ++k) a[k] -= a[k * p];
  }

  template <typename I, typename T>
  static void zeta_transform(map<I, T> &a) {
    for (auto &x : a)
      for (auto p = rbegin(a); p->first != x.first; p++)
        if (p->first % x.first == 0) x.second += p->second;
  }
  template <typename I, typename T>
  static void mobius_transform(map<I, T> &a) {
    for (auto p1 = rbegin(a); p1 != rend(a); p1++)
      for (auto p2 = rbegin(a); p2 != p1; p2++)
        if (p2->first % p1->first == 0) p1->second -= p2->second;
  }
};

/**
 * @brief 倍数変換・約数変換
 * @docs docs/multiplicative-function/divisor-multiple-transform.md
 */




// f(n, p, c) : n = pow(p, c), f is multiplicative function

template <typename T, T (*f)(int, int, int)>
struct enamurate_multiplicative_function {
  enamurate_multiplicative_function(int _n)
      : ps(prime_enumerate(_n)), a(_n + 1, T()), n(_n), p(ps.size()) {}

  vector<T> run() {
    a[1] = 1;
    dfs(-1, 1, 1);
    return a;
  }

 private:
  vector<int> ps;
  vector<T> a;
  int n, p;
  void dfs(int i, long long x, T y) {
    a[x] = y;
    if (y == T()) return;
    for (int j = i + 1; j < p; j++) {
      long long nx = x * ps[j];
      long long dx = ps[j];
      if (nx > n) break;
      for (int c = 1; nx <= n; nx *= ps[j], dx *= ps[j], ++c) {
        dfs(j, nx, y * f(dx, ps[j], c));
      }
    }
  }
};

/**
 * @brief 乗法的関数の列挙
 */

namespace multiplicative_function {
template <typename T>
T moebius(int, int, int c) {
  return c == 0 ? 1 : c == 1 ? -1 : 0;
}
template <typename T>
T sigma0(int, int, int c) {
  return c + 1;
}
template <typename T>
T sigma1(int n, int p, int) {
  return (n - 1) / (p - 1) + n;
}
template <typename T>
T totient(int n, int p, int) {
  return n - n / p;
}
}  // namespace multiplicative_function

template <typename T>
static constexpr vector<T> mobius_function(int n) {
  enamurate_multiplicative_function<T, multiplicative_function::moebius<T>> em(
      n);
  return em.run();
}

template <typename T>
static constexpr vector<T> sigma0(int n) {
  enamurate_multiplicative_function<T, multiplicative_function::sigma0<T>> em(
      n);
  return em.run();
}

template <typename T>
static constexpr vector<T> sigma1(int n) {
  enamurate_multiplicative_function<T, multiplicative_function::sigma1<T>> em(
      n);
  return em.run();
}

template <typename T>
static constexpr vector<T> totient(int n) {
  enamurate_multiplicative_function<T, multiplicative_function::totient<T>> em(
      n);
  return em.run();
}

/**
 * @brief 有名な乗法的関数
 * @docs docs/multiplicative-function/mf-famous-series.md
 */

using namespace Nyaan;

// k 番目に小さい
pl calc(ll N, ll K) {
  trc2(N, K);
  auto cnt = [&](Rational f) -> ll {
    vi v(N + 1);
    rep1(i, N) { v[i] = i * ll(f.x) / int(f.y); }
    divisor_transform::mobius_transform(v);
    trc2(f, Sum(v));
    return Sum(v);
  };
  Rational L{0, 1};
  Rational M{1, 2};
  Rational R{1, 1};
  while (true) {
    trc2(L.x, L.y, M.x, M.y, R.x, R.y);
    ll c = cnt(M);
    if (c == K) {
      break;
    }
    if (c < K) {
      for (int i = 1;; i *= 2) {
        Rational f{L.x + R.x * i, L.y + R.y * i};
        if (cnt(f) == K) return {f.x, f.y};
        if (cnt(f) < K) {
          L = f;
        } else {
          break;
        }
      }
    } else {
      for (int i = 1;; i *= 2) {
        Rational f{L.x * i + R.x, L.y * i + R.y};
        if (cnt(f) == K) return {f.x, f.y};
        if (cnt(f) >= K) {
          R = f;
        } else {
          break;
        }
      }
    }
    M = Rational{L.x + R.x, L.y + R.y};
  }
  return {M.x, M.y};
}

void q() {
  inl(N, K);
  vi tot(N + 10);
  rep(i, sz(tot)) tot[i] = i;
  divisor_transform::mobius_transform(tot);
  if (N <= 2) trc(tot);

  ll s = -1;
  rep1(i, N) s += tot[i];
  trc(s);
  ll p = -1, q = -1;
  if (K <= s) {
    tie(p, q) = calc(N, K);
  } else if (K == s + 1) {
    p = q = 1;
  } else if (K <= s * 2 + 1) {
    tie(q, p) = calc(N, 2 * s + 1 - (K - 1));
  } else {
    // do nothing
  }
  if (p == -1) {
    out(-1);
  } else {
    cout << p << "/" << q << "\n";
  }
}

void Nyaan::solve() {
  int t = 1;
  in(t);
  while (t--) q();
}