City Q and City R are 568 km apart. At 3.33 p.m., Zane is travelling at a uniform speed left City Q for City R while Ahmad set off from City R to City Q along the same road at a uniform speed, which was 6 km/h slower than that of Zane. The two met at 7.33 p.m.
- Find the speed of Zane.
- If Ahmad 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 Zane and Ahmad to travel from 3.33 p.m. to 7.33 p.m. = 4 h
Average speed of Zane and Ahmad
= 568 ÷ 4
= 142 km/h
Zane's speed
= (142 + 6) ÷ 2
= 148 ÷ 2
= 74 km/h
(b)
Ahmad's speed
= 74 - 6
= 68 km/h
Distance that Ahmad travelled in 4 h
= 4 x 68
= 272 km
Remaining distance that Ahmad needed to travel
= 568 - 272
= 296 km
Time that Ahmad needed to reach his destination after the two met
= 296 ÷ 68
= 4
2468 = 4
617 h
Answer(s): (a) 74 km/h; (b) 4
617 h