Percentage - Aptitude MCQ Questions and Solutions with Explanations

Answer: Option C

$$\eqalign{ & {\text{Required}}\,{\text{Percentage}} \cr & = \frac{{ {1.14 \times 100} }}{{1.9}} \cr & = 60\% \cr} $$

Answer: Option A

Students passed in English = 80%
Students passed in Math's = 85%
Students passed in both subjects = 73%
Then, number of students passed in at least one subject
= (80+85)-73
= 92%. [The percentage of students passed in English and Maths individually, have already included the percentage of students passed in both subjects. So, We are subtracting percentage of students who have passed in both subjects to find out percentage of students at least passed in one subject.]

Thus, students failed in both subjects = 100-92 = 8%.

Answer: Option C

$$\eqalign{ & {\text{As}}\,{\text{we}}\,{\text{know}},\,1\% = \frac{1}{{100}} \cr & {\text{Hence}},\, \cr & \frac{1}{2}\% = {\frac{1}{2} \times \frac{1}{{100}}} \cr & \,\,\,\,\,\,\,\,\,\,\, = \frac{1}{{200}} \cr & \,\,\,\,\,\,\,\,\,\,\, = 0.005 \cr} $$

Answer: Option B

Let the initial price of the commodity be 100.

After 50% increase in price, It will become,
100 ------50% increase----> 150.
Now, we have to reduce the consumption to keep expenditure 100.

Increase in price= 150 - 100 = 50
We have to reduce the consumption,
$$\eqalign{ & = \frac{{50}}{{150}} \times 100 \cr & = \frac{1}{3}{\text{ or 33}}{\text{.33}}\% \cr} $$

Other Method:
Here, we use, Final product constant graphic.
100 ==50% up== 150===33.33% down===>100
Consumption Reduce = 33.33% = $$\frac{1}{3}$$

Answer: Option C

Here we can use the compound interest based formula,
$$\eqalign{ & {\text{Population after }}n{\text{ years}} \cr & = P \times {\left[ {1 + {\frac{r}{{100}}} } \right]^n} \cr & {\text{Population after 2 years}} \cr & = 50000 \times {\left[ {1 + {\frac{4}{{100}}} } \right]^2} \cr} $$
Population after 2 years = 54080

Alternatively,
we can use, net percentage change graphic as well,
50,000------4%↑---→ 52,000---- 4%↑---→ 54,080.
Then, population after 2 years= 54,080.
In this calculation, we need to find 1% of 50,000 first, which is easily calculated by dividing 50,000 by 100.