A three-digit number is selected at random from the set of all three-digit numbers. The probability that the number selected has all the three digits same is `1//9` b. `1//10` c. `1//50` d. `1//100`

Options

A. `1//9`
B. `1//10`
C. `1//50`
D. `1//100`

Answer

D

Explanation

Three-digit numbers are 100, 101, …, 999. Total number of such numbers is 900. The three-digit numbers (which have all same digits) are 111, 222, 333, …, 999. Favorable number of cases is 9. Therefore, the probability is `9//900 = 1//100`.