City W and City X are 462 km apart. At 6.21 p.m., Reggie is travelling at a uniform speed left City W for City X while Jeremy set off from City X to City W along the same road at a uniform speed, which was 10 km/h slower than that of Reggie. The two met at 9.21 p.m.
- Find the speed of Reggie.
- 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 Reggie and Jeremy to travel from 6.21 p.m. to 9.21 p.m. = 3 h
Average speed of Reggie and Jeremy
= 462 ÷ 3
= 154 km/h
Reggie's speed
= (154 + 10) ÷ 2
= 164 ÷ 2
= 82 km/h
(b)
Jeremy's speed
= 82 - 10
= 72 km/h
Distance that Jeremy travelled in 3 h
= 3 x 72
= 216 km
Remaining distance that Jeremy needed to travel
= 462 - 216
= 246 km
Time that Jeremy needed to reach his destination after the two met
= 246 ÷ 72
= 3
3072 = 3
512 h
Answer(s): (a) 82 km/h; (b) 3
512 h