City U and City V are 432 km apart. At 5.56 p.m., Julian is travelling at a uniform speed left City U for City V while Ian set off from City V to City U along the same road at a uniform speed, which was 8 km/h slower than that of Julian. The two met at 8.56 p.m.
- Find the speed of Julian.
- If Ian 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 Julian and Ian to travel from 5.56 p.m. to 8.56 p.m. = 3 h
Average speed of Julian and Ian
= 432 ÷ 3
= 144 km/h
Julian's speed
= (144 + 8) ÷ 2
= 152 ÷ 2
= 76 km/h
(b)
Ian's speed
= 76 - 8
= 68 km/h
Distance that Ian travelled in 3 h
= 3 x 68
= 204 km
Remaining distance that Ian needed to travel
= 432 - 204
= 228 km
Time that Ian needed to reach his destination after the two met
= 228 ÷ 68
= 3
2468 = 3
617 h
Answer(s): (a) 76 km/h; (b) 3
617 h