City C and City D are 592 km apart. At 4.13 p.m., Andy is travelling at a uniform speed left City C for City D while Ken set off from City D to City C along the same road at a uniform speed, which was 12 km/h slower than that of Andy. The two met at 8.13 p.m.
- Find the speed of Andy.
- 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 Andy and Ken to travel from 4.13 p.m. to 8.13 p.m. = 4 h
Average speed of Andy and Ken
= 592 ÷ 4
= 148 km/h
Andy's speed
= (148 + 12) ÷ 2
= 160 ÷ 2
= 80 km/h
(b)
Ken's speed
= 80 - 12
= 68 km/h
Distance that Ken travelled in 4 h
= 4 x 68
= 272 km
Remaining distance that Ken needed to travel
= 592 - 272
= 320 km
Time that Ken needed to reach his destination after the two met
= 320 ÷ 68
= 4
4868 = 4
1217 h
Answer(s): (a) 80 km/h; (b) 4
1217 h