City Z and City A are 488 km apart. At 1.25 p.m., Jenson is travelling at a uniform speed left City Z for City A while Justin set off from City A to City Z along the same road at a uniform speed, which was 10 km/h slower than that of Jenson. The two met at 5.25 p.m.
- Find the speed of Jenson.
- If Justin 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 Jenson and Justin to travel from 1.25 p.m. to 5.25 p.m. = 4 h
Average speed of Jenson and Justin
= 488 ÷ 4
= 122 km/h
Jenson's speed
= (122 + 10) ÷ 2
= 132 ÷ 2
= 66 km/h
(b)
Justin's speed
= 66 - 10
= 56 km/h
Distance that Justin travelled in 4 h
= 4 x 56
= 224 km
Remaining distance that Justin needed to travel
= 488 - 224
= 264 km
Time that Justin needed to reach his destination after the two met
= 264 ÷ 56
= 4
4056 = 4
57 h
Answer(s): (a) 66 km/h; (b) 4
57 h