City V and City W are 450 km apart. At 3.48 p.m., Sam is travelling at a uniform speed left City V for City W while Cody set off from City W to City V along the same road at a uniform speed, which was 10 km/h slower than that of Sam. The two met at 6.48 p.m.
- Find the speed of Sam.
- If Cody 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 Cody to travel from 3.48 p.m. to 6.48 p.m. = 3 h
Average speed of Sam and Cody
= 450 ÷ 3
= 150 km/h
Sam's speed
= (150 + 10) ÷ 2
= 160 ÷ 2
= 80 km/h
(b)
Cody's speed
= 80 - 10
= 70 km/h
Distance that Cody travelled in 3 h
= 3 x 70
= 210 km
Remaining distance that Cody needed to travel
= 450 - 210
= 240 km
Time that Cody needed to reach his destination after the two met
= 240 ÷ 70
= 3
3070 = 3
37 h
Answer(s): (a) 80 km/h; (b) 3
37 h