Question

A number is divisible by both 13 and 6 .Find the other number which is always divisible by that number

Answer 1

Factors of 13 = 1, 13

Factors of 6 = 1, 2, 3, 6

13 and 6 are co-primes, and we know that if a number is divisible by two co-primes, then it is a known fact that it is also divisible by their product.

The product of and 12 is 78. Hence, the number is always divisible by 78.