City E and City F are 369 km apart. At 1.28 p.m., Eric is travelling at a uniform speed left City E for City F while Ivan set off from City F to City E along the same road at a uniform speed, which was 9 km/h slower than that of Eric. The two met at 4.28 p.m.
- Find the speed of Eric.
- If Ivan 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 Eric and Ivan to travel from 1.28 p.m. to 4.28 p.m. = 3 h
Average speed of Eric and Ivan
= 369 ÷ 3
= 123 km/h
Eric's speed
= (123 + 9) ÷ 2
= 132 ÷ 2
= 66 km/h
(b)
Ivan's speed
= 66 - 9
= 57 km/h
Distance that Ivan travelled in 3 h
= 3 x 57
= 171 km
Remaining distance that Ivan needed to travel
= 369 - 171
= 198 km
Time that Ivan needed to reach his destination after the two met
= 198 ÷ 57
= 3
2757 = 3
919 h
Answer(s): (a) 66 km/h; (b) 3
919 h