A super difficult application problem!! Urgently, I m going to do the math soon!

Chengbei Primary School wants to buy 60 balls, and there are three stores to choose from, and the unit price of the balls in the three stores is 30 yuan, but the preferential policies of each store are different!!

A: Buy 10 or more, get 2 free.

B: $4 discount per ball.

C: If you purchase over 100 yuan, you will get 15 yuan back.

To reduce expenses, which store should schools go to to buy?

Solution: A(60-60 10*2)*30=1440 B60*(30-4)=1560

C 60 * 30 - 60 * 30 100 * 15 = 1530 A: Obviously, A is the cheapest.

Cost to store A: (60-50 10 2) 30 = 1500 (yuan) cost to store B: 60 (30-4) = 1560 (yuan) cost to store C:

60 30-60 30 100 15=1530 (yuan) The school should go to store A to buy.

Solution: A(60-60 10*2)*30=1440 B60*(30-4)=1560

C 60 * 30 - 60 * 30 100 * 15 = 1530 is obviously the cheapest A.

There are 177 science and technology books, story books and literature books, assuming that there are 2 more science and technology books and 3 less story books at this time, and the literature and art books remain the same, there are a total of 177 + 2-3 = 176 books at this time.

If at this time the literary book is divided by 2. It is the same as the number of science and technology books and story books, and if this state is maintained at this time, then we can know.

Literary books = 2 times science and technology books = 2 times story books.

So at this time, science and technology books = story books = 176 4 = 44 original science and technology books = 44-2 = 42

The original storybook 44 + 3 = 47

The original literary book = 44 * 2 = 88

There are 2 more science and technology books, with 177+2

If there are 3 fewer storybooks, then 177 + 2-3 = 176

Divide the literary books by 2, then there are the same number of books in the three books, then divide 176 into four equal parts, and each copy is the same number of books 176 4 = 44

44-2=42 There are 42 science and technology books.

44+3=47 There are 47 storybooks.

44 2=88 There are 88 literary books.

The following relationship can be obtained from the question:

Science & Technology Book +2 = Storybook -3 = Literature Book 2

The equation is listed as:

Literary books + (literary books 2) - 2 + (literary books 2) + 3 = 177 (books) Solution: There are 88 literary and artistic books.

42 science and technology books.

47 storybooks.

(1) If a number is 51, what is 2/3 of it?

2) How many fractions of a 6 is 5 points 3 more than 6?

Eighty-eight discount**, which means that spending 12% less money, is 480 yuan cheaper.

480 divided by 12% = 4000 yuan.

The original price is 4000 yuan.

480 (100 -88) = 4000 yuan.

A: The original price of this computer is 4,000 yuan.

Analysis: Discounting 88% means reducing to 88 of the original price

And 480 cheaper means that the original price is 480 less than the current price

So 480 will be equal to 100 -88 = 12 of the original price Solution: The original price of this computer is: 480 12 = 4000 Answer: The original price of this computer is 4000 yuan.

480÷（1-88%）

4000 yuan.

Absolutely, I'm also in 6th grade