Which one of the following numbers is divisible by 15 ?

Answer: Option A

Consider the number is 17325
Its unit digit is 5, so it is divisible by 5
Sum of its digits = (5 + 2 + 3 + 7 + 1) = 18, which is divisible by 3
So, the given number is divisible by 3
And since 5 and 3 are co-primes,
So the given number is divisible by (5 × 3), i.e., 15