City N and City P are 465 km apart. At 6.48 p.m., Charlie is travelling at a uniform speed left City N for City P while Jenson set off from City P to City N along the same road at a uniform speed, which was 5 km/h slower than that of Charlie. The two met at 9.48 p.m.
- Find the speed of Charlie.
- If Jenson 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 Jenson to travel from 6.48 p.m. to 9.48 p.m. = 3 h
Average speed of Charlie and Jenson
= 465 ÷ 3
= 155 km/h
Charlie's speed
= (155 + 5) ÷ 2
= 160 ÷ 2
= 80 km/h
(b)
Jenson's speed
= 80 - 5
= 75 km/h
Distance that Jenson travelled in 3 h
= 3 x 75
= 225 km
Remaining distance that Jenson needed to travel
= 465 - 225
= 240 km
Time that Jenson needed to reach his destination after the two met
= 240 ÷ 75
= 3
1575 = 3
15 h
Answer(s): (a) 80 km/h; (b) 3
15 h