City V and City W are 354 km apart. At 4.59 p.m., Ken is travelling at a uniform speed left City V for City W while Wesley set off from City W to City V along the same road at a uniform speed, which was 10 km/h slower than that of Ken. The two met at 7.59 p.m.
- Find the speed of Ken.
- If Wesley 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 Ken and Wesley to travel from 4.59 p.m. to 7.59 p.m. = 3 h
Average speed of Ken and Wesley
= 354 ÷ 3
= 118 km/h
Ken's speed
= (118 + 10) ÷ 2
= 128 ÷ 2
= 64 km/h
(b)
Wesley's speed
= 64 - 10
= 54 km/h
Distance that Wesley travelled in 3 h
= 3 x 54
= 162 km
Remaining distance that Wesley needed to travel
= 354 - 162
= 192 km
Time that Wesley needed to reach his destination after the two met
= 192 ÷ 54
= 3
3054 = 3
59 h
Answer(s): (a) 64 km/h; (b) 3
59 h