City Y and City Z are 460 km apart. At 3.53 p.m., John is travelling at a uniform speed left City Y for City Z while Valen set off from City Z to City Y along the same road at a uniform speed, which was 11 km/h slower than that of John. The two met at 7.53 p.m.
- Find the speed of John.
- If Valen 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 John and Valen to travel from 3.53 p.m. to 7.53 p.m. = 4 h
Average speed of John and Valen
= 460 ÷ 4
= 115 km/h
John's speed
= (115 + 11) ÷ 2
= 126 ÷ 2
= 63 km/h
(b)
Valen's speed
= 63 - 11
= 52 km/h
Distance that Valen travelled in 4 h
= 4 x 52
= 208 km
Remaining distance that Valen needed to travel
= 460 - 208
= 252 km
Time that Valen needed to reach his destination after the two met
= 252 ÷ 52
= 4
4452 = 4
1113 h
Answer(s): (a) 63 km/h; (b) 4
1113 h