City C and City D are 548 km apart. At 2.57 p.m., Jenson is travelling at a uniform speed left City C for City D while Vaidev set off from City D to City C along the same road at a uniform speed, which was 9 km/h slower than that of Jenson. The two met at 6.57 p.m.
- Find the speed of Jenson.
- If Vaidev 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 Jenson and Vaidev to travel from 2.57 p.m. to 6.57 p.m. = 4 h
Average speed of Jenson and Vaidev
= 548 ÷ 4
= 137 km/h
Jenson's speed
= (137 + 9) ÷ 2
= 146 ÷ 2
= 73 km/h
(b)
Vaidev's speed
= 73 - 9
= 64 km/h
Distance that Vaidev travelled in 4 h
= 4 x 64
= 256 km
Remaining distance that Vaidev needed to travel
= 548 - 256
= 292 km
Time that Vaidev needed to reach his destination after the two met
= 292 ÷ 64
= 4
3664 = 4
916 h
Answer(s): (a) 73 km/h; (b) 4
916 h