City T and City U are 440 km apart. At 6.39 p.m., John is travelling at a uniform speed left City T for City U while Warren set off from City U to City T along the same road at a uniform speed, which was 10 km/h slower than that of John. The two met at 8.39 p.m.
- Find the speed of John.
- If Warren 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 John and Warren to travel from 6.39 p.m. to 8.39 p.m. = 2 h
Average speed of John and Warren
= 440 ÷ 2
= 220 km/h
John's speed
= (220 + 10) ÷ 2
= 230 ÷ 2
= 115 km/h
(b)
Warren's speed
= 115 - 10
= 105 km/h
Distance that Warren travelled in 2 h
= 2 x 105
= 210 km
Remaining distance that Warren needed to travel
= 440 - 210
= 230 km
Time that Warren needed to reach his destination after the two met
= 230 ÷ 105
= 2
20105 = 2
421 h
Answer(s): (a) 115 km/h; (b) 2
421 h