City J and City K are 456 km apart. At 6.51 p.m., Ryan is travelling at a uniform speed left City J for City K while Cody set off from City K to City J along the same road at a uniform speed, which was 12 km/h slower than that of Ryan. The two met at 8.51 p.m.
- Find the speed of Ryan.
- If Cody 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 Ryan and Cody to travel from 6.51 p.m. to 8.51 p.m. = 2 h
Average speed of Ryan and Cody
= 456 ÷ 2
= 228 km/h
Ryan's speed
= (228 + 12) ÷ 2
= 240 ÷ 2
= 120 km/h
(b)
Cody's speed
= 120 - 12
= 108 km/h
Distance that Cody travelled in 2 h
= 2 x 108
= 216 km
Remaining distance that Cody needed to travel
= 456 - 216
= 240 km
Time that Cody needed to reach his destination after the two met
= 240 ÷ 108
= 2
24108 = 2
29 h
Answer(s): (a) 120 km/h; (b) 2
29 h