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

Question

Philoid · Accepted Answer

Total numbers of elementary events are: 10 x 9= 90

Being numbers are of non-replacing nature and order matters

Let E be the event of a/b as an integer

Favorable events are:

2/1, 3/1 , 4/1, 4/2, 5/1 , 6/1, 6/2 , 6/3 , 7/1 , 8/4 , 8/2 , 8/1, 9/3 , 9/1 , 10/5 , 10/2 , 10/1

Numbers of favorable outcomes are: 17/90

P (a/b is an integer) = P (E) = 17/90