City W and City X are 350 km apart. At 3.49 p.m., Harry is travelling at a uniform speed left City W for City X while Rael set off from City X to City W along the same road at a uniform speed, which was 7 km/h slower than that of Harry. The two met at 5.49 p.m.
- Find the speed of Harry.
- If Rael 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 Harry and Rael to travel from 3.49 p.m. to 5.49 p.m. = 2 h
Average speed of Harry and Rael
= 350 ÷ 2
= 175 km/h
Harry's speed
= (175 + 7) ÷ 2
= 182 ÷ 2
= 91 km/h
(b)
Rael's speed
= 91 - 7
= 84 km/h
Distance that Rael travelled in 2 h
= 2 x 84
= 168 km
Remaining distance that Rael needed to travel
= 350 - 168
= 182 km
Time that Rael needed to reach his destination after the two met
= 182 ÷ 84
= 2
1484 = 2
16 h
Answer(s): (a) 91 km/h; (b) 2
16 h