A math add on, math add on?

A total of (1+12)*12 2=78 eggs were taken out, and if they were all 50 grams, they weighed a total of 78 * 50 = 3900 grams, and now they weigh 10 grams.

Each 50-gram egg is 3 grams lighter, and each 50-gram egg is 55 grams heavier, and the front should be the same, don't equation, right?

The 5-gram heavier and 3-gram lighter ones weigh 10 grams.

Therefore, 3 weights of 5 grams and 5 light weights of 3 grams are put together to offset the weight of lightness, and then put 2 weights of 5 grams is exactly 10 grams more.

But in this way, there are 2 boxes that take 5 of each, and it is not true.

Therefore, 6 weights of 5 grams and 10 light weights of 3 grams are put together to offset the weight of lightness, and 2 weights of 5 grams are just 10 grams more.

In this way, 8 of the heavier ones were taken, and 3 of the lighter ones were taken 10 pieces.

47 g of eggs in the 10th box.

55 g of eggs in the 8th box.

55 grams of eggs are 5 grams more than 50 grams, and the total extra is 10 in the end, so the number of 47 grams should be a multiple of 5, and there are two cases: 5 and 10.

If 47 grams of eggs are in the 5th box, 3*5=15

So 55 grams of eggs are also in the 5th box, which is contradictory.

Then 47 grams of eggs are in the 10th box, so 55 grams of eggs are in the 8th box.

A total of (1+12)*12 2=78 eggs (know this), assuming that all the eggs are 50g, then: 78*50=3900g, but now it is 3910, which is 10g more

One is 3G lighter and the other is 5G heavier

If the two numbers are the same, then 2g more is to be in box 5, this is just an assumption, the two boxes can not be the same, starting from 55g, the multiple of 5 g5 can only end in 5 or 0.

And the multiples of 3 are different, there are many possibilities, now to 10g more, it is necessary to make the light 3g eggs less than the sum of the eggs of 5g, so the box number of 3 can only be within 5 or 10, only two can be made, the sum of the weight of light 3g eggs is 5 or 0 end, = the above proves that 5 is not good, then the eggs of 47 are in the 10th, then the 55g is in the (3 * 10 + 10) 5 = 8.

1.First of all, because the sum of 78 eggs is 3910g is an integer, so a 47g egg can only be the 5th box or.

is the 10th cell, so that the final sum will be an integer.

1) If the 47g egg is in the 5th box, then take out 5*47=235g from the 5th box, then it is left.

The number of eggs is 73 and 3675gAnd if 3675-(73*50)=15,15 5=3

So 55g of eggs are in the 3rd compartment.

2) If the 47g egg is in the 10th grid, so take out 10*47=470 from the 10th grid, then it is left.

That's 68 eggs and 3910-470 = 3440gThere is because 3440-(68*50)=40,40 5

8, so 55g eggs are in the 8th box.

To sum up, there are two answers.

Buying 3 barrels is 8 more doughnuts than buying 2 barrels, and the amount of money required to buy 3 barrels is 16 + 8 = 24 yuan.

Therefore, the ** row of the donuts buried in the skin is 24 8 = 3 yuan.

There is a total of 3x16+8=56 yuan.

This is a proportional assignment problem.

First of all, find out how much each serving is

8-5) 30 copies.

Science and technology books: 30x8=240 books.

Storybook: 30x5 150 copies.

1. A and B have completed 1 3, (i.e. B cents = 1000 3 2 = 1000 6).

2. B and C complete the remaining 2 3 of 1 4, = 1 6, (B cents = 1000 6 2 = 1000 12).

B's salary = 1000 6 + 1000 12 = 250 yuan.

The sum of the diameters of the two circles is equal to the length of the sides of the rectangle.

Friend, we need two conditions for a rectangle, one is long and the other is wide, and we can't find any conditions for width or to get wide from the title.

Good luck.

Let the newborn be x mm.

Then 20 days is x*2 (20-1)=20

Divide by 2 at the same time

x*2^（20-1-2）=5

That is, at 18 days, the worm is 5 mm long.

It took 18 days to grow to 20 mm, 19 days to 10 mm, and 18 days to 5 mm.

5 mm on 18 days, 10 mm on 19 days, and exactly 20 mm on 20 days, so it's 18 days.

20 mm for 18 days, 10 mm for 19 days, 5 mm for 18 days.

In 2006, the father's age was x, the mother's age was y, Lu Kai's brother's age was a, and his brother's age was b

In 2006, x+y = 78 and a+b = 17

In 2010, x+4=4(b+4), y+4=3(a+4) solution was called x=40, y=38, a=10, b=7 after 2006, and then m year, 40+m=3(10+m), and m=5

Let the side length of the square be m, then.

m:(m+5)=7:(m+7)，7m+35=m²+7m，m²=35

Area of the square = 35

A total of 8 people need: 400 8=3200 (ml).

Store A: 2 large bottles get 2 small bottles + 2 small bottles for a total of 3200ml, pay 24 yuan B store: 2 large bottles + 4 small bottles for a total of 3200ml, pay yuan C store: 30 yuan can be 3 large bottles of a total of 3600ml, 24 yuan after 20% off C store is the most cost-effective.

Dried apples are 100 (1-99%) = 1 gram.

So now the mass is 1 (1-98%) = 50 grams.

Contains 100 apples (1-99%) = 1 kg.

The water content is reduced to 98%, and the apple content is 2%.

Thus the total mass 1 2% = 50 kg.

100kg of apples with a water content of 99%.

99kg of water, net weight of pulp 1kg

After a week, the water content dropped to 98%.

Total mass of apples = 1 (1-98%) = 50kg

Except for the decrease in water, the weight of other substances in apples is basically unchanged.

Set the mass to be mkg

So there is (m=50kg.)

So the total mass of the apple is 50kg