Trevor is currently 11 years old and his older brother is 20 years old. How old will Trevor be when his older brother is three times as old as Trevor is now? Think carefully first, then make a decision:
When Trevor is 11, his older brother will be 11 x 3 = 33 years old. Trevor’s older brother is 20 - 11 = 9 years older than Trevor. Since Trevor is 9 years younger, Trevor will be 33 - 9 = 24 years old. So, the answer is 24.