Question

Two numbers 'a' and 'b'are selected, successively without replacement in that order, from integers 1 to 10. The probability that a/b is an integer, is ______.

Answer 1

Two numbers 'a' and 'b'are selected, successively without replacement in that order, from integers 1 to 10. The probability that a/b is an integer, is `underlinebb(17/90)`.

Explanation:

There are \[10\times9=90\] ordered pairs. There are 17 pairs with distinct entries for which b divides a.

Therefore, the probability is \[\frac{17}{90}\].