City D and City E are 357 km apart. At 1.48 p.m., Bobby is travelling at a uniform speed left City D for City E while Zane set off from City E to City D along the same road at a uniform speed, which was 11 km/h slower than that of Bobby. The two met at 4.48 p.m.
- Find the speed of Bobby.
- If Zane 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 Bobby and Zane to travel from 1.48 p.m. to 4.48 p.m. = 3 h
Average speed of Bobby and Zane
= 357 ÷ 3
= 119 km/h
Bobby's speed
= (119 + 11) ÷ 2
= 130 ÷ 2
= 65 km/h
(b)
Zane's speed
= 65 - 11
= 54 km/h
Distance that Zane travelled in 3 h
= 3 x 54
= 162 km
Remaining distance that Zane needed to travel
= 357 - 162
= 195 km
Time that Zane needed to reach his destination after the two met
= 195 ÷ 54
= 3
3354 = 3
1118 h
Answer(s): (a) 65 km/h; (b) 3
1118 h