City P and City Q are 508 km apart. At 5.46 p.m., Tommy is travelling at a uniform speed left City P for City Q while George set off from City Q to City P along the same road at a uniform speed, which was 7 km/h slower than that of Tommy. The two met at 9.46 p.m.
- Find the speed of Tommy.
- If George continued to travel at the same speed, how long would it take for him to reach his destination after the two met? Express your answer in mixed number.
(a)
Time taken for Tommy and George to travel from 5.46 p.m. to 9.46 p.m. = 4 h
Average speed of Tommy and George
= 508 ÷ 4
= 127 km/h
Tommy's speed
= (127 + 7) ÷ 2
= 134 ÷ 2
= 67 km/h
(b)
George's speed
= 67 - 7
= 60 km/h
Distance that George travelled in 4 h
= 4 x 60
= 240 km
Remaining distance that George needed to travel
= 508 - 240
= 268 km
Time that George needed to reach his destination after the two met
= 268 ÷ 60
= 4
2860 = 4
715 h
Answer(s): (a) 67 km/h; (b) 4
715 h