Simple Equations(7th Grade > Mathematics ) Questions and answers for exam Preparation

7th Grade > Mathematics

SIMPLE EQUATIONS MCQs

Total Questions : 118 | Page 1 of 12 pages

Question 1. In a triangle ABC, angle A is half of B and angle C is thrice of A. Find the value of angle A, B and C? [4 MARKS]

Discuss Question

:
Concept: 1 Mark
Framing of the equation: 1 Mark
Steps: 1 Mark
Result: 1 Mark
Let the value of angle B be

y^{\circ}

Then, value of angle

A = \frac{y^{\circ}}{2}

And, value of angle

C = \frac{3 y^{\circ}}{2}

We know that sum of all angles in a triangle is

180^{\circ}

\Rightarrow y^{\circ} + \frac{y^{\circ}}{2} + \frac{3 y^{\circ}}{2} = 180^{\circ}

\Rightarrow 3 y^{\circ} = 180^{\circ}

\Rightarrow y^{\circ} = 60^{\circ} =

Value of angle B
So,Value of angle

A = \frac{y^{\circ}}{2} = 30^{\circ}

Value of angle

C = \frac{3 y^{\circ}}{2} = 90^{\circ}

Question 2. After buying a toy from the shop, I am left with ₹15 from my 100 rupees of pocket money. Then, the cost of toy (in rupees) is:

Discuss Question

Answer: Option C. -> 85
:
C
Let the cost of the toy be x as it is the unknown.
x + 15 = 100
x = 100 - 15 =₹85
So, the cost of the toy=₹85

Question 3. In the equation

x = 10 y - 24

, sum of the coefficients of dependent and independent variables is ___.

Discuss Question

:
The value of

x

depends on the value of

y

. So the dependent variable is x and the independent variable is y.
Sum of the coefficients of dependent and independent variable

= (10 + 1) = 11

Question 4. The sum of a number and its half is five less than twice the number. Which of the following equations represents given statement mathematically?

x+x2 = (2x−5)
x+a2 = (5−2x)
x+a2 = (5−2a)
a+x2 = 2x−5

Discuss Question

Answer: Option A. -> x+x2 = (2x−5)
:
A

Let the number be ' x'.

Half of the number is \frac{x}{2} .

Similarly, twice of the number = 2 x .

Sum of the number and its half = x + \frac{x}{2}

5 less than twice the number = 2 x - 5

Given: Sum of the number and its half is five less than twice of the number.

∴ The required equation is x + \frac{x}{2} = 2 x - 5

Question 5. The sum of three consecutive numbers is

36

. Find the numbers.

12,13,14
10,11,12
11,12,13
13,12,11

Discuss Question

Answer: Option C. -> 11,12,13
:
C
Let the first number be

a

.
So the three consecutive numbers will be

a, a + 1, a + 2

a +a +1 +a +2 = 36

\Rightarrow

3a +3 = 36

\Rightarrow

3a = 36 -3 = 33

\Rightarrow

a = \frac{33}{3} = 11

So, the three consecutive numbers will be

11, 12, 13

Question 6. Find x, when

\frac{3 x + 5}{7} = \frac{16}{7}

. [2 MARKS]

Discuss Question

:
Steps: 1 Mark
Result: 1 Mark

\frac{3 x + 5}{7} = \frac{16}{7}

Or,

(3 x + 5) \times 7 = 16 \times 7

Or,

21 x + 35 = 112

Or,

21 x = 112 - 35

Or,

21 x = 77

Or,

x = \frac{77}{21} = \frac{11}{3}

Question 7. (a) Aditya has a certain number of pencils. The cost of pencils is 10 greater than 4 times the number of pencils which Aditya has. The total cost of the pencils is Rs 162. Frame the equation and find the number of pencils.
(b) People of Sundargram planted a total of 102 trees in the village garden. Some of the trees were fruit trees. The number of non-fruit trees was two more than three times the number of fruit trees. What was the number of fruit trees? [4 MARKS]

Discuss Question

:
(a)Steps: 1 Mark
Result: 1 Mark
(b)Steps: 1 Mark
Result: 1 Mark
(a) Let Aditya have x pencils
Now 4 times the number of pencils which Aditya has is