中二級數學
2012-04-08 7:30 am
2.) In a bag, there are pieces of sweets and chocolates in the ratio 4:7. After Miss Lung has added 10 pieces of sweets to the bag, the ratio of sweets to chocolates becomes 6:7. How many pieces of chocolates are there in the bag?
回答 (2)
2012-04-08 7:47 am
✔ 最佳答案
Pieces of chocolates in the bag:(10/(6-4))*7
=35
2012-04-08 3:17 pm
Let no. of chocolate = x and no. of sweet = y.
So y : x = 4 : 7
that is y/x = 4/7 or 7y = 4x ...............(1)
After adding 10 pcs of sweet, quantity of sweet = y + 10
So (y + 10) : x = 6 : 7
that is (y + 10)/x = 6/7
7(y + 10) = 6x
7y + 70 = 6x ................(2)
Sub (1) into (2)
4x + 70 = 6x
2x = 70
x = 35 = No. of chocolates.
So y : x = 4 : 7
that is y/x = 4/7 or 7y = 4x ...............(1)
After adding 10 pcs of sweet, quantity of sweet = y + 10
So (y + 10) : x = 6 : 7
that is (y + 10)/x = 6/7
7(y + 10) = 6x
7y + 70 = 6x ................(2)
Sub (1) into (2)
4x + 70 = 6x
2x = 70
x = 35 = No. of chocolates.
收錄日期: 2021-04-25 22:38:01
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120407000051KK00912