[ Hint: Assume Gray meets Connie after travelling for X hours.]
How to do it
更新1:
點解？？？
MATH F.1
2008-03-11 4:14 am
Gray drives a car at a speed of 80 km/h from city A to city B. At the same time , Louisa and Connie drives at a speed of 60km/h and 65km/h respectively from city B to city A .If Gray meets Louisa 30 minutes after he has met Connie,find the distance between city A to city B.
[ Hint: Assume Gray meets Connie after travelling for X hours.]
How to do it
[ Hint: Assume Gray meets Connie after travelling for X hours.]
How to do it
回答 (2)
2008-03-11 4:23 am
✔ 最佳答案
As follows~圖片參考：http://i248.photobucket.com/albums/gg191/ncy_0916/f1maths.jpg?t=1205151822
2008-03-11 4:39 am
Distance travelled by Gray +
distance travelled by Connie when they met each other = AB
&
Distance travelled by Gray
distance travelled by Louisa when they met each other = AB
30 minutes = 0.5 hour
80X+65X = 80(X+0.5)+60(X+0.5)
145X = 140X + 70
X=14
∴ Gray meets Connie after travelling for 14 hours
The distance between city A to city B = 80(14)+65(14)
= 2030 km
distance travelled by Connie when they met each other = AB
&
Distance travelled by Gray
distance travelled by Louisa when they met each other = AB
30 minutes = 0.5 hour
80X+65X = 80(X+0.5)+60(X+0.5)
145X = 140X + 70
X=14
∴ Gray meets Connie after travelling for 14 hours
The distance between city A to city B = 80(14)+65(14)
= 2030 km
收錄日期: 2021-04-23 20:41:57
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080310000051KK02518