City C and City D are 486 km apart. At 5.48 p.m., Eric 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 6 km/h slower than that of Eric. The two met at 8.48 p.m.
- Find the speed of Eric.
- 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 Eric and Ken to travel from 5.48 p.m. to 8.48 p.m. = 3 h
Average speed of Eric and Ken
= 486 ÷ 3
= 162 km/h
Eric's speed
= (162 + 6) ÷ 2
= 168 ÷ 2
= 84 km/h
(b)
Ken's speed
= 84 - 6
= 78 km/h
Distance that Ken travelled in 3 h
= 3 x 78
= 234 km
Remaining distance that Ken needed to travel
= 486 - 234
= 252 km
Time that Ken needed to reach his destination after the two met
= 252 ÷ 78
= 3
1878 = 3
313 h
Answer(s): (a) 84 km/h; (b) 3
313 h