City Q and City R are 460 km apart. At 5.43 p.m., Harry is travelling at a uniform speed left City Q for City R while Riordan set off from City R to City Q along the same road at a uniform speed, which was 10 km/h slower than that of Harry. The two met at 7.43 p.m.
- Find the speed of Harry.
- If Riordan 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 Riordan to travel from 5.43 p.m. to 7.43 p.m. = 2 h
Average speed of Harry and Riordan
= 460 ÷ 2
= 230 km/h
Harry's speed
= (230 + 10) ÷ 2
= 240 ÷ 2
= 120 km/h
(b)
Riordan's speed
= 120 - 10
= 110 km/h
Distance that Riordan travelled in 2 h
= 2 x 110
= 220 km
Remaining distance that Riordan needed to travel
= 460 - 220
= 240 km
Time that Riordan needed to reach his destination after the two met
= 240 ÷ 110
= 2
20110 = 2
211 h
Answer(s): (a) 120 km/h; (b) 2
211 h