City L and City M are 378 km apart. At 4.10 p.m., Pierre is travelling at a uniform speed left City L for City M while Bryan set off from City M to City L along the same road at a uniform speed, which was 6 km/h slower than that of Pierre. The two met at 7.10 p.m.
- Find the speed of Pierre.
- If Bryan 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 Pierre and Bryan to travel from 4.10 p.m. to 7.10 p.m. = 3 h
Average speed of Pierre and Bryan
= 378 ÷ 3
= 126 km/h
Pierre's speed
= (126 + 6) ÷ 2
= 132 ÷ 2
= 66 km/h
(b)
Bryan's speed
= 66 - 6
= 60 km/h
Distance that Bryan travelled in 3 h
= 3 x 60
= 180 km
Remaining distance that Bryan needed to travel
= 378 - 180
= 198 km
Time that Bryan needed to reach his destination after the two met
= 198 ÷ 60
= 3
1860 = 3
310 h
Answer(s): (a) 66 km/h; (b) 3
310 h