City L and City M are 483 km apart. At 2.58 p.m., Michael is travelling at a uniform speed left City L for City M while Albert set off from City M to City L along the same road at a uniform speed, which was 7 km/h slower than that of Michael. The two met at 5.58 p.m.
- Find the speed of Michael.
- If Albert 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 Michael and Albert to travel from 2.58 p.m. to 5.58 p.m. = 3 h
Average speed of Michael and Albert
= 483 ÷ 3
= 161 km/h
Michael's speed
= (161 + 7) ÷ 2
= 168 ÷ 2
= 84 km/h
(b)
Albert's speed
= 84 - 7
= 77 km/h
Distance that Albert travelled in 3 h
= 3 x 77
= 231 km
Remaining distance that Albert needed to travel
= 483 - 231
= 252 km
Time that Albert needed to reach his destination after the two met
= 252 ÷ 77
= 3
2177 = 3
311 h
Answer(s): (a) 84 km/h; (b) 3
311 h