City M and City N are 350 km apart. At 4.42 p.m., Harry is travelling at a uniform speed left City M for City N while Archie set off from City N to City M along the same road at a uniform speed, which was 7 km/h slower than that of Harry. The two met at 6.42 p.m.
- Find the speed of Harry.
- If Archie 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 Archie to travel from 4.42 p.m. to 6.42 p.m. = 2 h
Average speed of Harry and Archie
= 350 ÷ 2
= 175 km/h
Harry's speed
= (175 + 7) ÷ 2
= 182 ÷ 2
= 91 km/h
(b)
Archie's speed
= 91 - 7
= 84 km/h
Distance that Archie travelled in 2 h
= 2 x 84
= 168 km
Remaining distance that Archie needed to travel
= 350 - 168
= 182 km
Time that Archie 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