City H and City J are 360 km apart. At 4.16 p.m., Ahmad is travelling at a uniform speed left City H for City J while Warren set off from City J to City H along the same road at a uniform speed, which was 6 km/h slower than that of Ahmad. The two met at 7.16 p.m.
- Find the speed of Ahmad.
- 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 Ahmad and Warren to travel from 4.16 p.m. to 7.16 p.m. = 3 h
Average speed of Ahmad and Warren
= 360 ÷ 3
= 120 km/h
Ahmad's speed
= (120 + 6) ÷ 2
= 126 ÷ 2
= 63 km/h
(b)
Warren's speed
= 63 - 6
= 57 km/h
Distance that Warren travelled in 3 h
= 3 x 57
= 171 km
Remaining distance that Warren needed to travel
= 360 - 171
= 189 km
Time that Warren needed to reach his destination after the two met
= 189 ÷ 57
= 3
1857 = 3
619 h
Answer(s): (a) 63 km/h; (b) 3
619 h