Percentage - Aptitude MCQ Questions and Solutions with Explanations

Let the salary of A and B be 100x each and C be 100y
Money donate by A = 100x × $$\frac{{10}}{{100}}$$ = 10x
Money donate by B = 100x × $$\frac{8}{{100}}$$ = 8x
Money donate by C = 100y × $$\frac{9}{{100}}$$ = 9y
According to the question
⇒ 10x - 8x = 400
⇒ 2x = 400
⇒ x = 200
Total donation of A and B = 10x + 8x = 18x
⇒ 18 × 200 = 3600
The total donation by A and B is Rs. 900 more than that of C
⇒ 3600 - 9y = 900
⇒ 9y = 2700
⇒ y = 300
Monthly salary of C = 100y = 100 × 300 = 30000
∴ Monthly salary of C is Rs. 30000

Price × Quantity = Expenditure, if expenditure is fix. then,

⇒ 90 kg Rice → Rs. 5400
⇒ 1 kg Rice → Rs. 60

$$\eqalign{ & k \times \left( {k \times 30\% } \right) = k \times 270\% \cr & \Rightarrow k \times k \times \frac{{30}}{{100}} = k \times \frac{{270}}{{100}} \cr & \Rightarrow k = 9 \cr} $$

$$\eqalign{ & {\text{Let the number be }}x \cr & \frac{{x \times 40}}{{100}} = \frac{{x \times 60}}{{100}} - 30 \cr & 40x = 60x - 3000 \cr & 20x = 3000 \cr & x = 150 \cr & \frac{{x \times 20}}{{100}} = \frac{{150 \times 20}}{{100}} = 30 \cr} $$

$$\eqalign{ & {\text{C}} = \left( {{\text{A}} + {\text{B}}} \right) \times 40\% \cr & = \frac{{160 \times 40}}{{100}} \cr & = 64 \cr & {\text{B is more than C}} \cr & = \frac{{36}}{{64}} \times 100 \cr & = 56\frac{1}{4}\% \cr} $$

Given:
Salary of A is 30% more than salary of B
Calculation:
Let the salary of B be 100x
Salary of A = 100x + 100x × 30%
⇒ 130x
Percentage difference = $$\frac{{130{\text{x}} - 100{\text{x}}}}{{130{\text{x}}}} \times 100$$
= $$\frac{{30{\text{x}}}}{{130{\text{x}}}} \times 100$$
= 23.07% ≈ 23.1%
∴ B's salary is 23.1% less than that of A.

\[\begin{array}{*{20}{c}} {{\text{Income}}}&{{\text{Saving}}}&{{\text{Expenditure}}} \\ { \Rightarrow 100}&x&{100 - x} \\ { \Rightarrow 126}&{1.5x}&{120 - 1.2x} \end{array}\]
$$\eqalign{ & {\text{Now, Income }} - {\text{ Saving}} = {\text{Expenditure}} \cr & 126 - 1.5x = 120 - 1.2x \cr & 6 = 0.3x \cr & x = 20 \cr} $$

$$\eqalign{ & = \frac{{28}}{{128}} \times 100 \cr & = 21.875\% \cr & = 21.88\% \cr} $$

Given:
Salary of Mohit is 60% more than Vijay
Formula used:
Percentage = $$\frac{{{\text{Difference}}}}{{{\text{Larger value}}}} \times 100$$
Calculations:
Let the salary of Vijay = Rs. 100
⇒ So, the salary of Mohit = 100 + 60% of 100 = 100 + 60 = Rs. 160
According to the formula,
$$\eqalign{ & \Rightarrow {\text{Percentage}} = \frac{{{\text{Difference}}}}{{{\text{Larger value}}}} \times 100 \cr & = \frac{{160 - 100}}{{160}} \times 100 \cr & = \frac{{60}}{{160}} \times 100 \cr & = 37.5\% \cr} $$
Hence, the salary of Vijay and less than Mohit by 37.5%

Let total voters be 100%x
Total voters cast = Total votes % - % votes who did not cast vote
⇒ 100%x - 15%
⇒ 85%x
Votes got disqualified = 100
Thus, total votes cast = 85%x - 100
Winner got 45% of the total votes cast:
Loser got = 45% - 400
According to the question,
85%x - 100 = 45%x + 45%x - 400
⇒ 300 = 90%x - 85%x
⇒ 300 = 5%x
⇒ x = 6000
∴ The total number of voters is 6000