Skipping around a bit, I saw that #25 looked pretty easy. It was. I saw in the forums that someone had used binary search and a calculator which I thought was pretty clever, but mine was just brute force.

Problem #25

What is the first term in the Fibonacci sequence to contain 1000 digits?

Solution

max  = 10 ** 999
a, b, i = 1, 1, 2

while b < max
  i += 1
  a, b = b, b + a
end

puts i