City P and City Q are 426 km apart. At 4.50 p.m., Will is travelling at a uniform speed left City P for City Q while Ben set off from City Q to City P along the same road at a uniform speed, which was 10 km/h slower than that of Will. The two met at 7.50 p.m.
- Find the speed of Will.
- 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 Will and Ben to travel from 4.50 p.m. to 7.50 p.m. = 3 h
Average speed of Will and Ben
= 426 ÷ 3
= 142 km/h
Will's speed
= (142 + 10) ÷ 2
= 152 ÷ 2
= 76 km/h
(b)
Ben's speed
= 76 - 10
= 66 km/h
Distance that Ben travelled in 3 h
= 3 x 66
= 198 km
Remaining distance that Ben needed to travel
= 426 - 198
= 228 km
Time that Ben needed to reach his destination after the two met
= 228 ÷ 66
= 3
3066 = 3
511 h
Answer(s): (a) 76 km/h; (b) 3
511 h