There are 44 students in class 5 (2), including 24 boys and 20 girls. Boys account for ()% of the class

There are 44 students in class 5 (2), including 24 boys and 20 girls. Boys account for ()% of the class

24÷44×100%
≈0.545×100%
=54.5%

5、 There are 40 students in class 2, of which the number of boys is 2 / 3 of that of girls. How many girls?

24

There are 50 students in class 62, among which there are 8 more boys than girls. How many percent of the class are boys

If the number of male and female students is respectively X and y, then
X+Y=50
X - y = 8, x = 29, y = 21,;
So there are 29 boys, accounting for 58% of the class

Given that the first number is 7, the second number is 19, the third number is 31, the fourth number is 43, and the fifth number is 55, what is the nth number?

7+（n-1）12

The volume of a basketball is 9850 cubic centimeter. Find the radius r of the basketball (the volume of the ball v = 4 / 3 of the square of π R), and the result is accurate to 0.01 centimeter

The volume of a basketball is 9850 cubic centimeters. The radius r of the basketball (the volume of the ball v = 4 / 3 π r cube) is calculated, and the result is accurate to 0.01 cm
(9850 / 4 / 3 / π) open cube
About 2352.7 cubic meters
=13.30 cm

Please read the following dialogue carefully
Xiaoqiang: (10 yuan) grandfather, I'll buy a pen and a notebook
Salesman (grandfather): today is children's day. Pens are 10% off. Notebooks are sold to you at the marked price. If you buy both pens and notebooks, the money won't be enough
Xiaojun: Xiaoqiang, the price of pen is three times that of notebook. I'll lend you 1.1 yuan to buy these two things
According to the above dialogue, can you work out the price of pen and notebook separately?

Set X yuan per notebook
90%×3x+x=10+1.1
3.7x=11.1
x=3
3x = 3 × 3 = 9 yuan
Answer: 3 yuan for notebook and 9 yuan for pen

The natural numbers are arranged in the following triangular matrix according to the law. What is the number from the left of the first row in 2001?
one
2 3
6 5 4
7 8 9 10
15 14 13 12 11
……

Let 2001 be the nth row, then 1 + 2 + 3 +... + n = 2001
When n = 62, the sum is 1953; when n = 63, the sum is 2016;
So 2001 is line 63
It can be seen from the figure that the odd number line starts from the right and the even number line starts from the left
So 2001 is the 49th from the right of line 63
So 2001 is the 16th from the left of line 63

The sum of all negative integers with absolute values greater than 2 and less than 7 is

The sum of all negative integers with absolute values greater than 2 and less than 7 is - 18
-6-5-4-3=-18

Ninth grade geometry problem-solving, to be more difficult, had better add some algebra problems to be more difficult, about 20
Why is there no picture?

There are 8 yellow beads and 54 red beads. If you want to make a necklace, you should make the number of Red Beads 6 times that of yellow beads. If the number of yellow beads remains unchanged, how many red beads do you want to increase or decrease?

Reduce 6 Red Beads
54-6*8=6