A motorboat starts out and travels 9 miles per hour. In 3 hours another motorboat traveling 18 miles an hour starts to overtake the first one. In how many hours will the second boat overtake the first? Solution Let in T hours will the second boat overtake the first boat. The distance travelled by first boat in (T+3) hours =9x(T+3) miles (i) and The distance travelled by second boat in T hours =18 x T (ii) Thus by given condition 9(T+3)=18T T+3=(18T)/9 T+3=2T 3=2T-T T=3 hours. In 3 hours the second boat will overtake the first boat ..