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 x and y.
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