# Free Simple Equations 03 Practice Test - 7th grade

### Question 1

x+3=8 is called an algebraic ______.

variable

expression

equation

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.

### Question 2

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

4

2

3

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+2−2=4−2

∴y=2

### Question 3

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

#### SOLUTION

Solution :B

Let the number be x.

The other number is four times x,that is 4x.

Difference between them is 12: ⇒(4x−x)=12

Hence, the required equation is 4x−x=12.

### Question 4

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

196,98

96,192

19,38

250,125

#### SOLUTION

Solution :A

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

2x+x=300−6=294

3x=294

x=2943=98

So, Kohli scores 98 and Tony scores 196 runs.

### Question 5

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

13

−13

−23

23

#### SOLUTION

Solution :B

3z+72=52

6z+72=52 (by taking the LCM)

6z+72×2=52×2

6z+7=5

6z+7−7=5−7

6z=−2

6z6=−26

∴z=−13

### Question 6

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

#### SOLUTION

Solution :Let the number be x.

x−21=81

x=102

### Question 7

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

6x−3x=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,

42−7=35years

Sum of their present ages = 35 + 7 = 42

### Question 8

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

True

False

#### SOLUTION

Solution :B

4x+5−y=0 has two variables

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

### Question 9

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

True

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.

### Question 10

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