# Free Simple Equations 03 Practice Test - 7th grade

x+3=8 is called an algebraic ______.

A.

variable

B.

expression

C.

equation

D.

statement

#### SOLUTION

Solution : C

An algebraic expression having an equality sign is called an equation. An equation is a constraint placed on a variable which is in an expression.

The value of y that satisfies the equation 3(y+2)=12 is

A.

4

B.

2

C.

3

D.

7

#### SOLUTION

Solution : B

3(y+2)=12
Dividing both the sides of the equation by 3,
3(y+2)3=123y+2=4
Subtracting 2 from both the sides of the equation,
y+22=42
y=2

Frame an equation for the statement: "A number is four times another number and their difference is 12".

A. x+4x=12
B. 4xx=12
C. 4x=12
D. 5x=15

#### SOLUTION

Solution : B

Let the number be x.
The other number is four times x,that is 4x.

Difference between them is 12: (4xx)=12

Hence, the required equation is 4xx=12.

Tony scored twice as many runs as Kohli. Together they scored 6 runs short of triple century. How many runs did each score?

A.

196,98

B.

96,192

C.

19,38

D.

250,125

#### SOLUTION

Solution : A

Runs scored by Kohli be x. Then, runs scored by Tony will be 2x.

2x+x=3006=294
3x=294
x=2943=98
So, Kohli scores 98 and Tony scores 196 runs.

For the equation: 3z+72 = 52, 'z' is equal to ____.

A.

13

B.

13

C.

23

D.

23

#### SOLUTION

Solution : B

3z+72=52

6z+72=52    (by taking the LCM)

6z+72×2=52×2

6z+7=5

6z+77=57

6z=2

6z6=26

z=13

If a certain number when decreased by 21 becomes 81, what is the number?

___

#### SOLUTION

Solution :

Let the number be x.
x21=81
x=102

7 years  hence, Sarosh's father age will be thrice  that of Sarosh's age. Presently father's age is  6 times of Sarosh's age. Sum of their present ages is equal to:

___

#### SOLUTION

Solution : Let Sarosh's present age be x.
After  7 years  Sarosh's age will be x+7
and, his father's age will be 3(x+7).
This is equal to 6 times Sarosh's present age, i.e. =6x
So,
6x=3(x+7)=3x+21
6x3x=21
3x=21
x=7
Sarosh's present age is  7 years.

Father's age after  7 years is,
6×7=42years
His present age is,
427=35years

Sum of their present ages = 35 + 7 = 42

Is 4x+5y=0 a linear equation in one variable?

A.

True

B.

False

#### SOLUTION

Solution : B

4x+5y=0 has two variables x and y.

Therefore, 4x+5y is an equation in two variables.

x=3 is the solution of the equation x+3=0.

A.

True

B.

False

#### SOLUTION

Solution : B

The value of unknown variable which satisfies the equation is called solution of the equation.

So, substituting x=3, we get 3+3 i.e. 6 which is not equal to zero. So, 3 is not the solution of the equation.

Raju reads 23 rd of a book. He finds that still there are 100 pages to be read. The total number of pages in the book are?

#### SOLUTION

Solution :

If Raju reads 23 rd of a book. He will still have
13rd of the book to complete.
Let the total number of pages of the book be y
Then 13y=100
Hence y = 3  × 100
= 300