City B and City C are 492 km apart. At 4.37 p.m., Ethan is travelling at a uniform speed left City B for City C while Andy set off from City C to City B along the same road at a uniform speed, which was 8 km/h slower than that of Ethan. The two met at 7.37 p.m.
- Find the speed of Ethan.
- If Andy 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 Ethan and Andy to travel from 4.37 p.m. to 7.37 p.m. = 3 h
Average speed of Ethan and Andy
= 492 ÷ 3
= 164 km/h
Ethan's speed
= (164 + 8) ÷ 2
= 172 ÷ 2
= 86 km/h
(b)
Andy's speed
= 86 - 8
= 78 km/h
Distance that Andy travelled in 3 h
= 3 x 78
= 234 km
Remaining distance that Andy needed to travel
= 492 - 234
= 258 km
Time that Andy needed to reach his destination after the two met
= 258 ÷ 78
= 3
2478 = 3
413 h
Answer(s): (a) 86 km/h; (b) 3
413 h