Who won the race (need this within 6 hours)

Question

Bob and Carol are teenagers. Bob is two years older than Carol. If the digits of Carol's age are reversed, the new number would be three times as large as Bob's age Find Bob's age.

Answer 1

Annie, the reversed number has to be a multiple of 3 that ends in a 1. The way to know if any number is divisible by 3 is to add the digits. If the sum is divisible by 3, the entire number is divisible by 3.

 

Soooo, we have 21, 51, 81. 21/3 = 7, not in the teens. 51/3 = 17. 81/3 = 27.

 

Bob is 17 and Carol is 15.