City P and City Q are 356 km apart. At 6.19 p.m., Peter is travelling at a uniform speed left City P for City Q while Japheth set off from City Q to City P along the same road at a uniform speed, which was 10 km/h slower than that of Peter. The two met at 8.19 p.m.
- Find the speed of Peter.
- If Japheth 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 Peter and Japheth to travel from 6.19 p.m. to 8.19 p.m. = 2 h
Average speed of Peter and Japheth
= 356 ÷ 2
= 178 km/h
Peter's speed
= (178 + 10) ÷ 2
= 188 ÷ 2
= 94 km/h
(b)
Japheth's speed
= 94 - 10
= 84 km/h
Distance that Japheth travelled in 2 h
= 2 x 84
= 168 km
Remaining distance that Japheth needed to travel
= 356 - 168
= 188 km
Time that Japheth needed to reach his destination after the two met
= 188 ÷ 84
= 2
2084 = 2
521 h
Answer(s): (a) 94 km/h; (b) 2
521 h