Question

Aunt Elly’s favourite nephew visits her every 30 days. The other nephew visits her every 42 days. If both nephews visit Aunt Elly on one particular day, how long will be be before they both visit her again on the same day?

(I understand the question perfectly fine, I just don’t know how it exactly it wants me to answer it in a way. Please give me the explanation as well)

Answer 1

210 days

Explanation:

The way to solve this problem is to take the LCM (Least Common Multiple) of 30 and 42. Since the prime factorization of 30 is 2*3*5 and the prime factorization of 42 is 2*3*7, the LCM will be 2*3*5*7 which is 210.

Hope this helps :)