City Y and City Z are 600 km apart. At 2.10 p.m., Mark is travelling at a uniform speed left City Y for City Z while Caden set off from City Z to City Y along the same road at a uniform speed, which was 10 km/h slower than that of Mark. The two met at 7.10 p.m.
- Find the speed of Mark.
- If Caden 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 Mark and Caden to travel from 2.10 p.m. to 7.10 p.m. = 5 h
Average speed of Mark and Caden
= 600 ÷ 5
= 120 km/h
Mark's speed
= (120 + 10) ÷ 2
= 130 ÷ 2
= 65 km/h
(b)
Caden's speed
= 65 - 10
= 55 km/h
Distance that Caden travelled in 5 h
= 5 x 55
= 275 km
Remaining distance that Caden needed to travel
= 600 - 275
= 325 km
Time that Caden needed to reach his destination after the two met
= 325 ÷ 55
= 5
5055 = 5
1011 h
Answer(s): (a) 65 km/h; (b) 5
1011 h