There are 27 boys in class 6 (1) and two fifths of the class are girls. How many are there in class 6 (1)?

There are 27 boys in class 6 (1) and two fifths of the class are girls. How many are there in class 6 (1)?

Let the total number of people be X
27+(2/5)x=x
（3/5）x=27
x=45
There are 45 people in class six (1)

1. Look up ten mouths. (type one word) 2. Look down eight mouths. (type one word)

Ten ancient mouths
Eight mouths

If a, B and C buy a TV set together, 1 / 2 of the amount paid by a for several years is equal to 1 / 3 of the amount paid by B and 3 / 7 of the amount paid by C,
It is known that C paid 120 yuan more than A. how much is this TV set?

One half of a is equal to three seventh of C
7 / 14 of a is equal to 6 / 14 of C
The difference of 1 / 14 is 120 yuan,
The payment amount of C is 120 * 14 = 1680 yuan
The amount a pays is 1560 yuan
B pays 2340 yuan
The TV should be 5580 yuan
A paid 1560 yuan, B 2340 yuan, C 1680 yuan. Do you understand?

How to convert fractions into decimals
four
__
five
To decimals,

4 is the numerator and 5 is the denominator. Divide 4 by 5!

1. Number a is 8, which is 4 / 5 of number B, and number B is 5 / 7 of number C. what is the quotient of the sum of 2.3/5 plus the product of 5 / 6 and 2 / 5 divided by 7 / 9?

The C number is 8 / 4 / 5 / 5 / 7
=8*5/4*7/5
=14
2,（3/5+5/6*2/5）÷7/9
=（3/5+1/3）*9/7
=（9/15+5/15）*9/7
=14/15*9/7
=6/5

Bivariate linear equation (1) 1 / 2x-1 / 3 = 1
Bivariate linear equation (1) 1 / 2x-1 / 3 = 1 - 1 / 3x-y = 2 / 3 (2) 0.4x + 0.3y = 0.711x-10y = 1

(1) Multiply both sides of the first equation by 3 to get
3 / 2x-y = 3 take this formula minus the second one
11/6x=7/3
x=14/11
y=-12/11
（2）
0.4x+0.3y=0.7
4x+3y=7…… Formula 3
Formula 3 * 11-2 * 4 = 73y = 77-4
y=1
Substituting y into 11x-10y = 1
We get x = 1
So it's a good solution
x=1 y=1

How much is 80% of a number equal to 5 / 6 of 120?

120*5/6/80%=80

To solve the linear equations of three variables: x + y + Z = 6, Y-Z = 4, x-y-2z = 3,

x+y+z=6 (1)
y-z=4 (2)
x-y-2z=3 (3)
(1)-(3)=2y+3z=3
y-z=4
2y-2z=8
Simultaneously, z = - 1, y = 3, x = 4

A and B two workers produce a batch of parts, the work efficiency ratio is 2:1. After two days of joint production, they complete 60% of all tasks, and the rest is completed by B alone. How many days will it take to complete the task?

The efficiency of Party A and Party B is 2:1, two days of joint production, two days of Party B is only equivalent to one day of Party A, so two days of cooperation is equivalent to two + 1 = three days of Party A's own work, 60% / 3 = 20% per day, then Party B completes 20% / 2 = 10% per day. Therefore, it still needs (1-60%) / 10% = four days

How to solve 5 / 8x + 3 / 4Y = 58
Write steps

5/8X=58-3/4Y
X=(58-3/4Y)8/5
X=464/5-6/5Y
Is there another equation for this problem? You can solve it by substituting x into y