The probability that a randomly selected two digit positive integer will be a multiple of 11 is

Solution:
Number of sample space n(S):
Total number of two digit positive integers = 90
Favorable event P(A):
Two digit multiples of 11 =

Number of favorable outcome n(A):
Total number of two digit multiples of 11 = 9
Let us consider the requires probability as P(A); number of favorable outcomes as n(A) and the number of sample space as n(S).
The probability formula is as follows,

On substituting the values in the above formula we get,

On simplifying the above equation we get,

The required probability is
