City P and City Q are 592 km apart. At 5.24 p.m., Ivan is travelling at a uniform speed left City P for City Q while Perry set off from City Q to City P along the same road at a uniform speed, which was 12 km/h slower than that of Ivan. The two met at 9.24 p.m.
- Find the speed of Ivan.
- If Perry 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 Ivan and Perry to travel from 5.24 p.m. to 9.24 p.m. = 4 h
Average speed of Ivan and Perry
= 592 ÷ 4
= 148 km/h
Ivan's speed
= (148 + 12) ÷ 2
= 160 ÷ 2
= 80 km/h
(b)
Perry's speed
= 80 - 12
= 68 km/h
Distance that Perry travelled in 4 h
= 4 x 68
= 272 km
Remaining distance that Perry needed to travel
= 592 - 272
= 320 km
Time that Perry 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