City L and City M are 592 km apart. At 3.21 p.m., Daniel is travelling at a uniform speed left City L for City M while Flynn 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 7.21 p.m.
- Find the speed of Daniel.
- If Flynn 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 Flynn to travel from 3.21 p.m. to 7.21 p.m. = 4 h
Average speed of Daniel and Flynn
= 592 ÷ 4
= 148 km/h
Daniel's speed
= (148 + 12) ÷ 2
= 160 ÷ 2
= 80 km/h
(b)
Flynn's speed
= 80 - 12
= 68 km/h
Distance that Flynn travelled in 4 h
= 4 x 68
= 272 km
Remaining distance that Flynn needed to travel
= 592 - 272
= 320 km
Time that Flynn needed to reach his destination after the two met
= 320 ÷ 68
= 4
4868 = 4
1217 h
Answer(s): (a) 80 km/h; (b) 4
1217 h