Two cars A and B 250 km apart are travelling towards each other on the same road. The travelling speed of car B is 5 km/h more than 5/7 of the speed of car A. They will meet after 2 hours. Find the travelling speed of each car.
Answer should be in Algebra. Thank you.
Form 1 Algebra
2010-10-21 5:40 am
回答 (1)
2010-10-21 8:19 am
✔ 最佳答案
Let A be the speed of car ALet B be the speed of car B
B = 5 km +5/7A
The distance between them = 250 km
In 2 hours they have to cover 250 km together
250 km = speed of car A x time + speed of car B x time
250 km = A x 2 h + (5 +5/7A) x 2 h
250 = 2A + (10 +10/7A)
250 = 2A +10 +10/7A
2A +10/7A = 250 - 10
(14/7)A + (10/7)A = 240
(24/7) A = 240
A = 240(7)/24
A = 70 km/h
B = 5 km +(5/7)(70)
B = 5 + 50
B = 55 km/h
Speed of car A = 70 km/h
Speed o f car B = 55 km/h
收錄日期: 2021-04-29 16:56:22
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