Question

One is asked to say a two-digit number. What is the probability of it being a multiple of 9?

• A. 1/10
• B. 2/10
• C. 1/9
• D. 2/9

Answer 1

Answer:

C. 1/9

The total number of two-digit numbers is 99-10+1=90. The two-digit multiples of 9 are 8,27,36,45,54,63,72,81,90,99, There are 10 such numbers. Probability = number of multiples of 9/total number of two-digit number = 10/90 = 1/9