City L and City M are 396 km apart. At 6.31 p.m., Julian is travelling at a uniform speed left City L for City M while Neave set off from City M to City L along the same road at a uniform speed, which was 12 km/h slower than that of Julian. The two met at 9.31 p.m.
- Find the speed of Julian.
- If Neave 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 Neave to travel from 6.31 p.m. to 9.31 p.m. = 3 h
Average speed of Julian and Neave
= 396 ÷ 3
= 132 km/h
Julian's speed
= (132 + 12) ÷ 2
= 144 ÷ 2
= 72 km/h
(b)
Neave's speed
= 72 - 12
= 60 km/h
Distance that Neave travelled in 3 h
= 3 x 60
= 180 km
Remaining distance that Neave needed to travel
= 396 - 180
= 216 km
Time that Neave needed to reach his destination after the two met
= 216 ÷ 60
= 3
3660 = 3
35 h
Answer(s): (a) 72 km/h; (b) 3
35 h