City A and City B are 552 km apart. At 1.38 p.m., Billy is travelling at a uniform speed left City A for City B while Ben set off from City B to City A along the same road at a uniform speed, which was 8 km/h slower than that of Billy. The two met at 4.38 p.m.
- Find the speed of Billy.
- If Ben 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 Billy and Ben to travel from 1.38 p.m. to 4.38 p.m. = 3 h
Average speed of Billy and Ben
= 552 ÷ 3
= 184 km/h
Billy's speed
= (184 + 8) ÷ 2
= 192 ÷ 2
= 96 km/h
(b)
Ben's speed
= 96 - 8
= 88 km/h
Distance that Ben travelled in 3 h
= 3 x 88
= 264 km
Remaining distance that Ben needed to travel
= 552 - 264
= 288 km
Time that Ben needed to reach his destination after the two met
= 288 ÷ 88
= 3
2488 = 3
311 h
Answer(s): (a) 96 km/h; (b) 3
311 h