City F and City G are 378 km apart. At 2.57 p.m., Brandon is travelling at a uniform speed left City F for City G while Daniel set off from City G to City F along the same road at a uniform speed, which was 12 km/h slower than that of Brandon. The two met at 5.57 p.m.
- Find the speed of Brandon.
- If Daniel 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 Brandon and Daniel to travel from 2.57 p.m. to 5.57 p.m. = 3 h
Average speed of Brandon and Daniel
= 378 ÷ 3
= 126 km/h
Brandon's speed
= (126 + 12) ÷ 2
= 138 ÷ 2
= 69 km/h
(b)
Daniel's speed
= 69 - 12
= 57 km/h
Distance that Daniel travelled in 3 h
= 3 x 57
= 171 km
Remaining distance that Daniel needed to travel
= 378 - 171
= 207 km
Time that Daniel needed to reach his destination after the two met
= 207 ÷ 57
= 3
3657 = 3
1219 h
Answer(s): (a) 69 km/h; (b) 3
1219 h