City A and City B are 354 km apart. At 4.40 p.m., Will is travelling at a uniform speed left City A for City B while Luis set off from City B to City A along the same road at a uniform speed, which was 9 km/h slower than that of Will. The two met at 6.40 p.m.
- Find the speed of Will.
- If Luis 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 Luis to travel from 4.40 p.m. to 6.40 p.m. = 2 h
Average speed of Will and Luis
= 354 ÷ 2
= 177 km/h
Will's speed
= (177 + 9) ÷ 2
= 186 ÷ 2
= 93 km/h
(b)
Luis's speed
= 93 - 9
= 84 km/h
Distance that Luis travelled in 2 h
= 2 x 84
= 168 km
Remaining distance that Luis needed to travel
= 354 - 168
= 186 km
Time that Luis needed to reach his destination after the two met
= 186 ÷ 84
= 2
1884 = 2
314 h
Answer(s): (a) 93 km/h; (b) 2
314 h