City S and City T are 504 km apart. At 3.43 p.m., Ahmad is travelling at a uniform speed left City S for City T while Paul set off from City T to City S along the same road at a uniform speed, which was 6 km/h slower than that of Ahmad. The two met at 7.43 p.m.
- Find the speed of Ahmad.
- If Paul 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 Ahmad and Paul to travel from 3.43 p.m. to 7.43 p.m. = 4 h
Average speed of Ahmad and Paul
= 504 ÷ 4
= 126 km/h
Ahmad's speed
= (126 + 6) ÷ 2
= 132 ÷ 2
= 66 km/h
(b)
Paul's speed
= 66 - 6
= 60 km/h
Distance that Paul travelled in 4 h
= 4 x 60
= 240 km
Remaining distance that Paul needed to travel
= 504 - 240
= 264 km
Time that Paul needed to reach his destination after the two met
= 264 ÷ 60
= 4
2460 = 4
25 h
Answer(s): (a) 66 km/h; (b) 4
25 h