If four different balls are put into four red, yellow, blue and green boxes, there is exactly one empty box

If four different balls are put into four red, yellow, blue and green boxes, there is exactly one empty box

Choose two balls from four first. There are six kinds of balls
Choose 3 boxes and 4 kinds from 4 boxes
In the first two selected small balls to see one and the other two small balls into three boxes in six
So 6x4x3 = 72
I don't understand~

There are six red balls and six blue balls of the same size in the box. If you want to find three balls of the same color, how many balls should you find at least?
There are three red balls, five yellow balls and seven blue balls of the same size in the box. If you want to find out three balls of the same color, you need to find out at least a few balls, and you need to calculate the formula

Let's get at least x balls
3 + 5 + 7 = 15
3x =15
3x/3 = 15/3
x =5
5 + 1 = 6

Divide 15 apples into 5 parts, each part accounts for () of the total number of apples, and regard () as the unit "1", one fifth of the total number is () apples?
I'm in a hurry to help you

The 15 apples are divided into 5 parts on average, and each part accounts for (1 / 5) of the total number of apples. The (total number of apples) is regarded as the unit "1", and one fifth of the total number is (3) apples

The 10 apples were divided into 5 parts, each with (2) apples, each accounting for ()

1 / 5

Divide 15 apples into 5 piles, and the quantity of each pile is different. How many apples are there in the pile with the most apples?

1+2+3+4+5=15
The biggest pile is probably five

Divide 15 apples into 5 parts on average. The unit here is ()

Divide 15 apples into 5 parts on average. The unit here is (1 / 5)
Units here should refer to fractional units

On the construction site, 6 tons of concrete is prepared with 1 part of cement, 2 parts of yellow sand and 3 parts of stones. Is 10 bags of cement of the brand as shown in the figure enough? 50 kg of conch water
We need the formula!

10 bags is 500 kg of cement
500 + 1000 + 1500 = 3000 kg = 3 tons, only 3 tons of concrete can be used, but 6 tons of concrete is not enough

Which four digits can be represented by an upper and a lower bead on the abacus? Please write it down

Seven numbers of 500, 150, 105, 100, 510, 501, 5006000 can be represented by one upper and one lower bead on the abacus

On the tens of millions of positions of the abacus, what is the largest number represented by three beads

In the tens of millions of positions of the abacus, the largest number represented by three beads is 70 million

Which four digits can be represented by an upper and a lower bead on the abacus? Please write it down

Seven numbers of 500, 150, 105, 100, 510, 501, 5006000 can be represented by one upper and one lower bead on the abacus