Question

What is the probability that it is a multiple of 5, which is less than 200 ?

Hint:

To count multiples of a number 'k' in a range [a, b], you can calculate (b)/(k) - (a-1)/(k). Here, for multiples of 5 in [100, 199], it would be (199)/(5) - (99)/(5) = 39 - 19 = 20. This is a very fast method for large ranges.

Answer 1