City H and City J are 435 km apart. At 6.14 p.m., Sean is travelling at a uniform speed left City H for City J while Simon set off from City J to City H along the same road at a uniform speed, which was 5 km/h slower than that of Sean. The two met at 9.14 p.m.
- Find the speed of Sean.
- If Simon 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 Sean and Simon to travel from 6.14 p.m. to 9.14 p.m. = 3 h
Average speed of Sean and Simon
= 435 ÷ 3
= 145 km/h
Sean's speed
= (145 + 5) ÷ 2
= 150 ÷ 2
= 75 km/h
(b)
Simon's speed
= 75 - 5
= 70 km/h
Distance that Simon travelled in 3 h
= 3 x 70
= 210 km
Remaining distance that Simon needed to travel
= 435 - 210
= 225 km
Time that Simon needed to reach his destination after the two met
= 225 ÷ 70
= 3
1570 = 3
314 h
Answer(s): (a) 75 km/h; (b) 3
314 h