Question

Total number of $9$ -digit numbers that are divisible by $5$ is equal to

• A. $10^8$
• B. $9\times 10^7$
• C. $9\times 10^8$
• D. $18\times 10^7$

Answer 1

Answer: (D)

A number is divisible by 5 if it either ends with 5 or with zero.
(i) Total number ending with zero $=9\cdot 10^7$
(ii) Total number ending with $5=9\cdot 10^7$
Thus, total number of such numbers $=18\cdot 10^7$