City E and City F are 393 km apart. At 4.40 p.m., Wesley is travelling at a uniform speed left City E for City F while Ken set off from City F to City E along the same road at a uniform speed, which was 11 km/h slower than that of Wesley. The two met at 7.40 p.m.
- Find the speed of Wesley.
- If Ken 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 Wesley and Ken to travel from 4.40 p.m. to 7.40 p.m. = 3 h
Average speed of Wesley and Ken
= 393 ÷ 3
= 131 km/h
Wesley's speed
= (131 + 11) ÷ 2
= 142 ÷ 2
= 71 km/h
(b)
Ken's speed
= 71 - 11
= 60 km/h
Distance that Ken travelled in 3 h
= 3 x 60
= 180 km
Remaining distance that Ken needed to travel
= 393 - 180
= 213 km
Time that Ken needed to reach his destination after the two met
= 213 ÷ 60
= 3
3360 = 3
1120 h
Answer(s): (a) 71 km/h; (b) 3
1120 h