City A and City B are 426 km apart. At 2.38 p.m., Ahmad is travelling at a uniform speed left City A for City B while Japheth set off from City B to City A along the same road at a uniform speed, which was 9 km/h slower than that of Ahmad. The two met at 4.38 p.m.
- Find the speed of Ahmad.
- 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 Ahmad and Japheth to travel from 2.38 p.m. to 4.38 p.m. = 2 h
Average speed of Ahmad and Japheth
= 426 ÷ 2
= 213 km/h
Ahmad's speed
= (213 + 9) ÷ 2
= 222 ÷ 2
= 111 km/h
(b)
Japheth's speed
= 111 - 9
= 102 km/h
Distance that Japheth travelled in 2 h
= 2 x 102
= 204 km
Remaining distance that Japheth needed to travel
= 426 - 204
= 222 km
Time that Japheth needed to reach his destination after the two met
= 222 ÷ 102
= 2
18102 = 2
317 h
Answer(s): (a) 111 km/h; (b) 2
317 h