Susan, Arthur, Tom and, Bob are siblings. Arthur is 2 years older than Susan, and Tom is 3 years younger than Bob. If Bob is 11 years old, and Susan is 15 years old, how old are all four family members in total? Think carefully first, then make a decision:
Arthur is 2 years older than Susan, so he is 15 + 2 = 17 years old. Bob is 11 years old, so Tom is 11 - 3 = 8 years old. So in total these four family members have 11 + 15 + 17 + 8 = 51 years. So, the answer is 51.