City Y and City Z are 516 km apart. At 6.27 p.m., George is travelling at a uniform speed left City Y for City Z while Ben set off from City Z to City Y along the same road at a uniform speed, which was 12 km/h slower than that of George. The two met at 9.27 p.m.
- Find the speed of George.
- If Ben 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 George and Ben to travel from 6.27 p.m. to 9.27 p.m. = 3 h
Average speed of George and Ben
= 516 ÷ 3
= 172 km/h
George's speed
= (172 + 12) ÷ 2
= 184 ÷ 2
= 92 km/h
(b)
Ben's speed
= 92 - 12
= 80 km/h
Distance that Ben travelled in 3 h
= 3 x 80
= 240 km
Remaining distance that Ben needed to travel
= 516 - 240
= 276 km
Time that Ben needed to reach his destination after the two met
= 276 ÷ 80
= 3
3680 = 3
920 h
Answer(s): (a) 92 km/h; (b) 3
920 h