City D and City E are 432 km apart. At 5.12 p.m., Oliver is travelling at a uniform speed left City D for City E while Vincent set off from City E to City D along the same road at a uniform speed, which was 8 km/h slower than that of Oliver. The two met at 7.12 p.m.
- Find the speed of Oliver.
- If Vincent 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 Vincent to travel from 5.12 p.m. to 7.12 p.m. = 2 h
Average speed of Oliver and Vincent
= 432 ÷ 2
= 216 km/h
Oliver's speed
= (216 + 8) ÷ 2
= 224 ÷ 2
= 112 km/h
(b)
Vincent's speed
= 112 - 8
= 104 km/h
Distance that Vincent travelled in 2 h
= 2 x 104
= 208 km
Remaining distance that Vincent needed to travel
= 432 - 208
= 224 km
Time that Vincent needed to reach his destination after the two met
= 224 ÷ 104
= 2
16104 = 2
213 h
Answer(s): (a) 112 km/h; (b) 2
213 h