City M and City N are 378 km apart. At 3.12 p.m., Oliver is travelling at a uniform speed left City M for City N while Howard set off from City N to City M along the same road at a uniform speed, which was 6 km/h slower than that of Oliver. The two met at 6.12 p.m.
- Find the speed of Oliver.
- If Howard 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 Oliver and Howard to travel from 3.12 p.m. to 6.12 p.m. = 3 h
Average speed of Oliver and Howard
= 378 ÷ 3
= 126 km/h
Oliver's speed
= (126 + 6) ÷ 2
= 132 ÷ 2
= 66 km/h
(b)
Howard's speed
= 66 - 6
= 60 km/h
Distance that Howard travelled in 3 h
= 3 x 60
= 180 km
Remaining distance that Howard needed to travel
= 378 - 180
= 198 km
Time that Howard needed to reach his destination after the two met
= 198 ÷ 60
= 3
1860 = 3
310 h
Answer(s): (a) 66 km/h; (b) 3
310 h