City L and City M are 360 km apart. At 2.57 p.m., Oscar is travelling at a uniform speed left City L for City M while Jeremy set off from City M to City L along the same road at a uniform speed, which was 10 km/h slower than that of Oscar. The two met at 4.57 p.m.
- Find the speed of Oscar.
- If Jeremy 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 Oscar and Jeremy to travel from 2.57 p.m. to 4.57 p.m. = 2 h
Average speed of Oscar and Jeremy
= 360 ÷ 2
= 180 km/h
Oscar's speed
= (180 + 10) ÷ 2
= 190 ÷ 2
= 95 km/h
(b)
Jeremy's speed
= 95 - 10
= 85 km/h
Distance that Jeremy travelled in 2 h
= 2 x 85
= 170 km
Remaining distance that Jeremy needed to travel
= 360 - 170
= 190 km
Time that Jeremy needed to reach his destination after the two met
= 190 ÷ 85
= 2
2085 = 2
417 h
Answer(s): (a) 95 km/h; (b) 2
417 h