City W and City X are 396 km apart. At 6.44 p.m., Sam is travelling at a uniform speed left City W for City X while Jenson set off from City X to City W along the same road at a uniform speed, which was 6 km/h slower than that of Sam. The two met at 8.44 p.m.
- Find the speed of Sam.
- If Jenson 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 Sam and Jenson to travel from 6.44 p.m. to 8.44 p.m. = 2 h
Average speed of Sam and Jenson
= 396 ÷ 2
= 198 km/h
Sam's speed
= (198 + 6) ÷ 2
= 204 ÷ 2
= 102 km/h
(b)
Jenson's speed
= 102 - 6
= 96 km/h
Distance that Jenson travelled in 2 h
= 2 x 96
= 192 km
Remaining distance that Jenson needed to travel
= 396 - 192
= 204 km
Time that Jenson needed to reach his destination after the two met
= 204 ÷ 96
= 2
1296 = 2
18 h
Answer(s): (a) 102 km/h; (b) 2
18 h