City F and City G are 390 km apart. At 6.17 p.m., Charlie is travelling at a uniform speed left City F for City G while John set off from City G to City F along the same road at a uniform speed, which was 5 km/h slower than that of Charlie. The two met at 8.17 p.m.
- Find the speed of Charlie.
- 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 Charlie and John to travel from 6.17 p.m. to 8.17 p.m. = 2 h
Average speed of Charlie and John
= 390 ÷ 2
= 195 km/h
Charlie's speed
= (195 + 5) ÷ 2
= 200 ÷ 2
= 100 km/h
(b)
John's speed
= 100 - 5
= 95 km/h
Distance that John travelled in 2 h
= 2 x 95
= 190 km
Remaining distance that John needed to travel
= 390 - 190
= 200 km
Time that John needed to reach his destination after the two met
= 200 ÷ 95
= 2
1095 = 2
219 h
Answer(s): (a) 100 km/h; (b) 2
219 h