Question

From the set {1, 2, 3, 4, 5}, two numbers a and b (a ≠ b) are chosen at random. The probability that `a/b` is an integer is:

Options

• `1/3`

• `1/4`

• `1/2`

• `3/5`

Answer 1

`bb(1/4)`

Explanation:

Sample Space = `{1/2, 1/3, 1/4, 1/5, 2/1, 2/3, 2/4, 2/5, 3/1, 3/2, 3/4, 3/5, 4/1, 4/2, 4/3, 4/5, 5/1, 5/2, 5/3, 5/4}`

Case in which `a/b` is an integer = `[2/1, 3/1, 4/1, 4/2, 5/1]`

The probability that `(a/b)` is an integer = `5/20` = `1/4`.