T = gets.to_i

T.times do
  r, k = gets.split.map(&:to_f)
  ans = 0.0
  no_hit = 1.0

  1.upto(k) do |i|
    if i == k
      ans += i * no_hit
    else
      ans += i * r * no_hit
      no_hit *= (1.0 - r)
    end
  end

  puts [ans, k].min
end