City J and City K are 522 km apart. At 4.11 p.m., Fred is travelling at a uniform speed left City J for City K while Albert set off from City K to City J along the same road at a uniform speed, which was 12 km/h slower than that of Fred. The two met at 7.11 p.m.
- Find the speed of Fred.
- 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 Fred and Albert to travel from 4.11 p.m. to 7.11 p.m. = 3 h
Average speed of Fred and Albert
= 522 ÷ 3
= 174 km/h
Fred's speed
= (174 + 12) ÷ 2
= 186 ÷ 2
= 93 km/h
(b)
Albert's speed
= 93 - 12
= 81 km/h
Distance that Albert travelled in 3 h
= 3 x 81
= 243 km
Remaining distance that Albert needed to travel
= 522 - 243
= 279 km
Time that Albert needed to reach his destination after the two met
= 279 ÷ 81
= 3
3681 = 3
49 h
Answer(s): (a) 93 km/h; (b) 3
49 h