City N and City P are 540 km apart. At 4.58 p.m., Liam is travelling at a uniform speed left City N for City P while Will 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 Liam. The two met at 8.58 p.m.
- Find the speed of Liam.
- If Will 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 Liam and Will to travel from 4.58 p.m. to 8.58 p.m. = 4 h
Average speed of Liam and Will
= 540 ÷ 4
= 135 km/h
Liam's speed
= (135 + 5) ÷ 2
= 140 ÷ 2
= 70 km/h
(b)
Will's speed
= 70 - 5
= 65 km/h
Distance that Will travelled in 4 h
= 4 x 65
= 260 km
Remaining distance that Will needed to travel
= 540 - 260
= 280 km
Time that Will needed to reach his destination after the two met
= 280 ÷ 65
= 4
2065 = 4
413 h
Answer(s): (a) 70 km/h; (b) 4
413 h