City C and City D are 456 km apart. At 3.23 p.m., Pierre is travelling at a uniform speed left City C for City D while Oliver set off from City D to City C along the same road at a uniform speed, which was 10 km/h slower than that of Pierre. The two met at 7.23 p.m.
- Find the speed of Pierre.
- If Oliver 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 Pierre and Oliver to travel from 3.23 p.m. to 7.23 p.m. = 4 h
Average speed of Pierre and Oliver
= 456 ÷ 4
= 114 km/h
Pierre's speed
= (114 + 10) ÷ 2
= 124 ÷ 2
= 62 km/h
(b)
Oliver's speed
= 62 - 10
= 52 km/h
Distance that Oliver travelled in 4 h
= 4 x 52
= 208 km
Remaining distance that Oliver needed to travel
= 456 - 208
= 248 km
Time that Oliver needed to reach his destination after the two met
= 248 ÷ 52
= 4
4052 = 4
1013 h
Answer(s): (a) 62 km/h; (b) 4
1013 h