City Z and City A are 360 km apart. At 3.39 p.m., Charlie is travelling at a uniform speed left City Z for City A while Tim set off from City A to City Z along the same road at a uniform speed, which was 6 km/h slower than that of Charlie. The two met at 6.39 p.m.
- Find the speed of Charlie.
- If Tim 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 Charlie and Tim to travel from 3.39 p.m. to 6.39 p.m. = 3 h
Average speed of Charlie and Tim
= 360 ÷ 3
= 120 km/h
Charlie's speed
= (120 + 6) ÷ 2
= 126 ÷ 2
= 63 km/h
(b)
Tim's speed
= 63 - 6
= 57 km/h
Distance that Tim travelled in 3 h
= 3 x 57
= 171 km
Remaining distance that Tim needed to travel
= 360 - 171
= 189 km
Time that Tim needed to reach his destination after the two met
= 189 ÷ 57
= 3
1857 = 3
619 h
Answer(s): (a) 63 km/h; (b) 3
619 h