City W and City X are 595 km apart. At 3.13 p.m., Ahmad is travelling at a uniform speed left City W for City X while Luke set off from City X to City W along the same road at a uniform speed, which was 9 km/h slower than that of Ahmad. The two met at 8.13 p.m.
- Find the speed of Ahmad.
- If Luke 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 Ahmad and Luke to travel from 3.13 p.m. to 8.13 p.m. = 5 h
Average speed of Ahmad and Luke
= 595 ÷ 5
= 119 km/h
Ahmad's speed
= (119 + 9) ÷ 2
= 128 ÷ 2
= 64 km/h
(b)
Luke's speed
= 64 - 9
= 55 km/h
Distance that Luke travelled in 5 h
= 5 x 55
= 275 km
Remaining distance that Luke needed to travel
= 595 - 275
= 320 km
Time that Luke needed to reach his destination after the two met
= 320 ÷ 55
= 5
4555 = 5
911 h
Answer(s): (a) 64 km/h; (b) 5
911 h