City C and City D are 344 km apart. At 5.59 p.m., Japheth is travelling at a uniform speed left City C for City D while Peter set off from City D to City C along the same road at a uniform speed, which was 12 km/h slower than that of Japheth. The two met at 7.59 p.m.
- Find the speed of Japheth.
- If Peter 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 Japheth and Peter to travel from 5.59 p.m. to 7.59 p.m. = 2 h
Average speed of Japheth and Peter
= 344 ÷ 2
= 172 km/h
Japheth's speed
= (172 + 12) ÷ 2
= 184 ÷ 2
= 92 km/h
(b)
Peter's speed
= 92 - 12
= 80 km/h
Distance that Peter travelled in 2 h
= 2 x 80
= 160 km
Remaining distance that Peter needed to travel
= 344 - 160
= 184 km
Time that Peter needed to reach his destination after the two met
= 184 ÷ 80
= 2
2480 = 2
310 h
Answer(s): (a) 92 km/h; (b) 2
310 h