Quantitative Aptitude

Percentage

482 Questions
All Successive Percentage Changes 177 Population Growth and Depreciation 103 Fractional Base Multiplication 58 Reverse More-Than and Less-Than Comparisons 38 Income, Expenditure, and Savings 33 Price and Consumption 30 Election Votes and Margins 10 Fake Weight and Faulty Measures 10 Venn Diagram Percentages 9 Passing Marks Shifts 5 Fresh vs. Dry Mixture 2

Percentage Questions

Multiple choice geography international development international development and world population and its impact on resources population growth and impact on resources reproductive health in humans

During the year $2013$, the real gross domestic product of a country increased by $8\%$ over the preceding year. During this year population of the country also got increased by $1.6\%$. In that particular country, the rate of growth of per capita income during $2013$ would be: 

  1. $6.4%$
  2. $9.6\%$
  3. $5.0\%$
  4. $12.8\%$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The growth rate of per capita income is approximately equal to the growth rate of real GDP minus the growth rate of the population. Here, real GDP increased by 8% and population increased by 1.6%. Subtracting the two gives 8% - 1.6% = 6.4%.

Multiple choice mathematics and statistics banks and simple interest introduction to interests introduction to interest introduction to interest payments

A factory kept increasing its output by the same percentage every year. Find the percentage if it is known that the output is doubled in the last two years.

  1. $47.53\%$
  2. $45.26\%$
  3. $43.42\%$
  4. $41.42\%$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Given that the output is doubled in last two years
Let the output before $2$ years be$= x$
Hence after two years it will be$= 2x$

so $n=2$
now using formula $=A=P(1+\frac{R}{100})^n$
Now put the value on given formula .
=> $2x=x(1+\frac{R}{100})^2$
=>$2=1(1+\frac{R}{100})^2$
=>$\sqrt2=1(1+\frac{R}{100})$
=>$\frac{R}{100}=\sqrt{2}-1=1.4142-1=0.4142$
$=>R=41.42\%$
so option D is correct.

Multiple choice mathematics and statistics banks and simple interest introduction to interests introduction to interest introduction to interest payments

The population of a village was $20,000$ and after $2$ years it become $22050$. What is the rate of increase per annum ?

  1. $10\%$
  2. $8\%$
  3. $5\%$
  4. $6\%$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

We know that

Final population $=$ (original population)$\times { \left( 1+\frac { Rate }{ 100 }  \right)  }^{ time }.$.........(i)
Here original population $=20000$,
final population $=22050$,
Time $=2$ yrs,
rate=?
Let the rate $=R$.
Substituting the values of the given parameters in (i),
$20000{ \left( 1+\dfrac { R }{ 100 }  \right)  }^{ 2 }=22050$
$ \Rightarrow { \left( 1+\dfrac { R }{ 100 }  \right)  }^{ 2 }=\dfrac { 22050 }{ 20000 } =1.1025$
$ \Rightarrow \left( 1+\dfrac { R }{ 100 }  \right) =\sqrt { 1.1025 } =1.05\  $
i.e $R=5\%$
Ans- Option C.

Multiple choice maths equation reducing simple equations to simpler form solving linear equations solution of a linear equation in one variable

After receiving two successive raises Hrash's salary became $\dfrac {15}{8}$ times of his initial salary. By how much percent was the salary raised the first time if the second raise was twice as much as high (in percent) as the first ?

  1. $15 \%$
  2. $20 \%$
  3. $25 \%$
  4. $30 \%$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let initial salary was Rs. $100$
After two raise it become $\dfrac {15}{8}$ i.e. $\dfrac {(15 \times 100) }{ 8} =$ Rs. $187.5$
Raise $= 187.5 - 100 = 87.5$
Using formula,
[( first raise  + second raise) + (first raise * 2nd raise) / 100]  = 87.5
$x + 2x +\dfrac { (2x ^2)}{100} = 87.53$
$300x + 2x ^2 = 8750$
$x ^2 + 150x = 4375$
$x ^2 + 150x - 4375 = 0$
$x ^2 + 175x - 25x - 4375 = 0$
$x = -175, 25$ .....(Negative value is not possible)
So, $x= 25\%$
Second raise was $2x = 2 \times 25 = 50\%$.

Multiple choice

If a number is increased by 20%, what is the percentage decrease required to bring it back to its original value?

  1. 16.67%

  2. 20%

  3. 25%

  4. 33.33%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let the original number be x. Increased number = x + 20% of x = x + 0.2x = 1.2x Percentage decrease required = (Increased number - Original number) / Increased number x 100% = (1.2x - x) / 1.2x x 100% = 0.2x / 1.2x x 100% = 20%.

Multiple choice

A population of bacteria grows exponentially with a growth rate of 0.5 per hour. If the initial population is 1000, what will be the population after 10 hours?

  1. 2500

  2. 5000

  3. 12500

  4. 25000
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using the exponential growth model, we can calculate the population at any given time.

Multiple choice

A population of rabbits grows exponentially with a growth rate of 0.75 per year. If the initial population is 1000, what will be the population after 5 years?

  1. 2013

  2. 3020

  3. 4027

  4. 5034
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using the exponential growth model, we can calculate the population at any given time.

Multiple choice

A company's sales have been increasing at a rate of 10% per year. If the company's sales were \$1 million last year, what will be the company's sales in 5 years?

  1. \$1.61 million
  2. \$1.5 million
  3. \$1.7 million
  4. \$1.8 million
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sales in 5 years will be the sales last year multiplied by (1 + 10%)^5. Therefore, the sales in 5 years will be \$1 million * (1 + 0.1)^5 = \$1.61 million.

Multiple choice

Gangaram buys 7000 bananas at Rs. 2 each and agrees to pay an additional sum of Rs. 300 for their delivery. He estimated that 10% of the bananas will be spoiled, so he decides a selling price of Rs. 3 each for the remaining. However, during delivery, 20% of the bananas are spoiled. What should be the percent increase in the selling price in order to obtain the same total profit?

  1. 20.5%

  2. 12.5%

  3. 25.6%

  4. 30.3%

  5. 35.4%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Initial cost: 7000 * 2 + 300 = 14300. Expected sales: 7000 * 0.9 * 3 = 18900. Profit = 4600. Actual sales: 7000 * 0.8 = 5600 bananas. To get 4600 profit, revenue must be 14300 + 4600 = 18900. New price = 18900 / 5600 = 3.375. Increase = (3.375 - 3) / 3 = 0.125 or 12.5%.

Multiple choice

There are 800 waiters in a hotel, of which 60% are males and the rest are females. The male waiters get a tip of 5% of the bill and the female waiters get a tip of 8% of the bill. If the ratio of the number of males to that of females gets reversed next year, but the total number of waiters remains the same, then find the percentage change in the total tip amount. (Assume that each male waiter gets an order of Rs. 600 and each female waiter gets an order of Rs. 500.)

  1. Decrease of 5.88%

  2. Increase of 5.28%

  3. Increase of 5.88%

  4. Decrease of 5.28%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Initial: 480 males (5% of 600 = 30 tip each), 320 females (8% of 500 = 40 tip each). Total tip = 480*30 + 320*40 = 14400 + 12800 = 27200. New: 320 males, 480 females. New tip = 320*30 + 480*40 = 9600 + 19200 = 28800. Change = (28800-27200)/27200 = 1600/27200 = 1/17 = 5.88%.