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Mathematical lollipop
1. The canteen manager took a sum of money to buy meat. If he bought 10 Jin of beef, it was 5 yuan short; if he bought 12 Jin of pork, it was more than 4 yuan short. It is known that beef is more expensive than pork per kilogram, 3 yuan. How much did the canteen manager bring?

Solution: Beef is more expensive than pork per kilogram, 3 yuan,

Then buy 10 kg pork than buy 10 kg beef, 30 yuan. 10×3=30 yuan

Buying 10 kg of beef is worse than 5 yuan, so buying 10 kg of pork is 30-5=25 yuan.

12 kg of pork has 4 yuan left, so 2 kg of pork =25-4=2 1 yuan.

Every kilogram of pork =2 1÷2= 10.5 yuan.

The administrator's money = 12× 10.5+4.

= 126+4

= 130 yuan

A: The canteen manager brought 130 yuan.

There are some apples and pears. There are three times as many apples as pears. If you eat two pears and five apples every day, there will be 20 apples when the pears are finished. Ask how many pears there are.

Solution: If you eat six apples a day, because the number of apples is three times that of pears, you should just finish them. But now there are 20 apples left, which means that you eat one less every day than the hypothetical situation (6 apples a day), which is equivalent to 20 days. You eat one less every day. That is to say, if you eat 6 apples a day for 20 days, then 20×2=40.

Formula: 20÷(6-5)=20 days to eat.

20× 2 = number of 40 pears

A: * * Here are 40 pears.

3. The difference between a pen and a ballpoint pen is 1.2 yuan, and the difference between the money Xiao Ming took to buy five pens is 1.5 yuan, and buying eight ballpoint pens is 0.60 yuan more. Ask Xiao Ming how much money he brought?

Analysis: In profit and loss problem, the formula we get refers to the same object. Now it's ballpoint pens and pens. Therefore, if we want to use the formula of profit and loss, we must turn it into the same object-a pen or a ballpoint pen.

Xiaoming bought five pens, and the price difference is 1.5 yuan. We can convert it into buying five ballpoint pens, because we know that the difference between pens and ballpoint pens is 1.2 yuan. If we buy five ballpoint pens instead of five pens, we will save 6 yuan money. 1.2×5=6 yuan.

Is worse than the original 1.5 yuan, but can be more 6-1.5 =4.5 yuan. In this way, we turned the original problem into: Xiaoming bought five ballpoint pens from 4.5 yuan and eight from 0.6 yuan. Ask Xiao Ming how much money he brought?

Then, the total profit and loss =4.5-0.6 =3.9 yuan,

Price of each ballpoint pen =3.9÷(8-5)= 1.3 yuan.

So Xiao Ming * * has 8×1.3+0.6 =11yuan.

Answer:

1.2×5=6 yuan

6- 1.5 =4.5 yuan

4.5-0.6 =3.9 yuan

3.9÷(8-5)= 1.3 yuan

8×1.3+0.6 =11yuan.

A: Xiao Ming brought 1 1 yuan.

There are some apples and pears. If there are 2 pears per 1 apple, there are 5 apples left when the pears are divided. If you pile three apples and five pears every day, there will be five pears left after the apples are divided. How many apples and pears are there?

Solution: If there are n apples and 2 pears (n-5), the equation is as follows:

n÷3=[2(n-5)-5]÷5

n÷3-2n÷5=- 15÷5

n÷ 15=3

N = 45 (apple)

2 (n-5) = 2× (45-5) = 80 pears.

There are 45 apples and 80 pears.

Checking calculation: (45-5) × 2 = 80,

(80-5)÷5=45÷3= 15

The calculation is correct.

The number of watermelons from fruit shop is four times that of cantaloupe. If you sell 130 watermelons and 36 cantaloupes every day, there will be 70 watermelons left after the cantaloupes are sold out. How many watermelons and cantaloupes are there in the fruit shop?

Analysis: This question is about the relationship between sum and difference times.

There is a multiple relationship before selling. If you sell 36 cantaloupes and 36× 4 watermelons every day, they will be sold out at the same time. Now, according to "130 watermelons and 36 cantaloupes",144-130 =14 cantaloupes are sold less every day.

36×4= 144

144- 130= 14

70÷ 14=5 days

5×( 130+36)+70

=5× 166+70

=630+70

=900

I asked the fruit shop about 900 watermelons and cantaloupes.

I hope it helps you!