City Z and City A are 540 km apart. At 2.30 p.m., Dylan is travelling at a uniform speed left City Z for City A while Sean set off from City A to City Z along the same road at a uniform speed, which was 12 km/h slower than that of Dylan. The two met at 5.30 p.m.
- Find the speed of Dylan.
- If Sean 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 Dylan and Sean to travel from 2.30 p.m. to 5.30 p.m. = 3 h
Average speed of Dylan and Sean
= 540 ÷ 3
= 180 km/h
Dylan's speed
= (180 + 12) ÷ 2
= 192 ÷ 2
= 96 km/h
(b)
Sean's speed
= 96 - 12
= 84 km/h
Distance that Sean travelled in 3 h
= 3 x 84
= 252 km
Remaining distance that Sean needed to travel
= 540 - 252
= 288 km
Time that Sean needed to reach his destination after the two met
= 288 ÷ 84
= 3
3684 = 3
37 h
Answer(s): (a) 96 km/h; (b) 3
37 h