City L and City M are 408 km apart. At 4.50 p.m., Daniel is travelling at a uniform speed left City L for City M while Ryan 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 Daniel. The two met at 6.50 p.m.
- Find the speed of Daniel.
- If Ryan 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 Daniel and Ryan to travel from 4.50 p.m. to 6.50 p.m. = 2 h
Average speed of Daniel and Ryan
= 408 ÷ 2
= 204 km/h
Daniel's speed
= (204 + 12) ÷ 2
= 216 ÷ 2
= 108 km/h
(b)
Ryan's speed
= 108 - 12
= 96 km/h
Distance that Ryan travelled in 2 h
= 2 x 96
= 192 km
Remaining distance that Ryan needed to travel
= 408 - 192
= 216 km
Time that Ryan needed to reach his destination after the two met
= 216 ÷ 96
= 2
2496 = 2
14 h
Answer(s): (a) 108 km/h; (b) 2
14 h