City A and City B are 540 km apart. At 2.23 p.m., Ethan is travelling at a uniform speed left City A for City B while Tommy set off from City B to City A along the same road at a uniform speed, which was 5 km/h slower than that of Ethan. The two met at 6.23 p.m.
- Find the speed of Ethan.
- If Tommy 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 Tommy to travel from 2.23 p.m. to 6.23 p.m. = 4 h
Average speed of Ethan and Tommy
= 540 ÷ 4
= 135 km/h
Ethan's speed
= (135 + 5) ÷ 2
= 140 ÷ 2
= 70 km/h
(b)
Tommy's speed
= 70 - 5
= 65 km/h
Distance that Tommy travelled in 4 h
= 4 x 65
= 260 km
Remaining distance that Tommy needed to travel
= 540 - 260
= 280 km
Time that Tommy needed to reach his destination after the two met
= 280 ÷ 65
= 4
2065 = 4
413 h
Answer(s): (a) 70 km/h; (b) 4
413 h