City R and City S are 462 km apart. At 5.22 p.m., Paul is travelling at a uniform speed left City R for City S while Sean set off from City S to City R along the same road at a uniform speed, which was 7 km/h slower than that of Paul. The two met at 7.22 p.m.
- Find the speed of Paul.
- If Sean 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 Paul and Sean to travel from 5.22 p.m. to 7.22 p.m. = 2 h
Average speed of Paul and Sean
= 462 ÷ 2
= 231 km/h
Paul's speed
= (231 + 7) ÷ 2
= 238 ÷ 2
= 119 km/h
(b)
Sean's speed
= 119 - 7
= 112 km/h
Distance that Sean travelled in 2 h
= 2 x 112
= 224 km
Remaining distance that Sean needed to travel
= 462 - 224
= 238 km
Time that Sean needed to reach his destination after the two met
= 238 ÷ 112
= 2
14112 = 2
18 h
Answer(s): (a) 119 km/h; (b) 2
18 h