City Z and City A are 600 km apart. At 4.30 p.m., Zeph is travelling at a uniform speed left City Z for City A while Neave 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 Zeph. The two met at 8.30 p.m.
- Find the speed of Zeph.
- If Neave 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 Zeph and Neave to travel from 4.30 p.m. to 8.30 p.m. = 4 h
Average speed of Zeph and Neave
= 600 ÷ 4
= 150 km/h
Zeph's speed
= (150 + 10) ÷ 2
= 160 ÷ 2
= 80 km/h
(b)
Neave's speed
= 80 - 10
= 70 km/h
Distance that Neave travelled in 4 h
= 4 x 70
= 280 km
Remaining distance that Neave needed to travel
= 600 - 280
= 320 km
Time that Neave needed to reach his destination after the two met
= 320 ÷ 70
= 4
4070 = 4
47 h
Answer(s): (a) 80 km/h; (b) 4
47 h