City A and City B are 528 km apart. At 5.11 p.m., Daniel is travelling at a uniform speed left City A for City B while John set off from City B to City A along the same road at a uniform speed, which was 12 km/h slower than that of Daniel. The two met at 9.11 p.m.
- Find the speed of Daniel.
- If John 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 Daniel and John to travel from 5.11 p.m. to 9.11 p.m. = 4 h
Average speed of Daniel and John
= 528 ÷ 4
= 132 km/h
Daniel's speed
= (132 + 12) ÷ 2
= 144 ÷ 2
= 72 km/h
(b)
John's speed
= 72 - 12
= 60 km/h
Distance that John travelled in 4 h
= 4 x 60
= 240 km
Remaining distance that John needed to travel
= 528 - 240
= 288 km
Time that John needed to reach his destination after the two met
= 288 ÷ 60
= 4
4860 = 4
45 h
Answer(s): (a) 72 km/h; (b) 4
45 h