Practice Percentage questions covering percentage change, increase and decrease, successive percentages, and conversions between percentages, fractions, and ratios for Quantitative Aptitude.
Question 2
A’s salary is 50% more than B’s. How much percent is B’s salary less than A’s?
Explanation
Let B's salary be 100. A's salary = 150.
B's salary is less than A's by 50150 × 100 = 3313%.
B's salary is less than A's by 50150 × 100 = 3313%.
Question 3
The price of cooking oil has increased by 25%. By what percent should a family reduce the consumption of cooking oil so as not to increase the expenditure in this account?
Explanation
Let the old price be 100 and the old consumption be 1 unit. The new price = 125.
To keep the expenditure the same, the new consumption = 100125 = 0.8 units.
The consumption is to be reduced by 20%.
To keep the expenditure the same, the new consumption = 100125 = 0.8 units.
The consumption is to be reduced by 20%.
Question 4
Ramesh’s salary was reduced by 10% and then the reduced salary was increased by 10%. What was his ultimate loss?
Explanation
After a decrease of 10% and an increase of 10%, the salary = 0.9 × 1.1 = 0.99 of the original.
The loss = 1%.
The loss = 1%.
Question 5
In a country 55% population is female. 80% of the male population is literate. How much of females are literate if total literacy is 58%?
Explanation
Females = 55% and males = 45% of the population.
Literate males = 80% of 45 = 36% of the population. Total literacy = 58%, so literate females = 58 - 36 = 22% of the population.
The percentage of literate females = 2255 × 100 = 40%.
Literate males = 80% of 45 = 36% of the population. Total literacy = 58%, so literate females = 58 - 36 = 22% of the population.
The percentage of literate females = 2255 × 100 = 40%.
Question 6
Two numbers are less than a third number by 30% and 37% respectively. How much percent is the second number less than the first?
Explanation
Let the third number be 100. The first number = 70 and the second number = 63.
The second is less than the first by 70 - 6370 × 100 = 10%.
The second is less than the first by 70 - 6370 × 100 = 10%.
Question 7
If 20% of an electricity bill is deducted, then Rs. 100 is still to be paid. How much was the original bill?
Explanation
After deducting 20%, the bill to be paid = 80% of the original = Rs. 100.
Original bill = 10080 × 100 = Rs. 125.
Original bill = 10080 × 100 = Rs. 125.
Question 8
5% of 5% of Rs. 100 is
Explanation
5% of Rs. 100 = Rs. 5, and 5% of Rs. 5 = Rs. 0.25.
Question 9
The price of apple is first increased by 10% and then decreased by 10%. What is the change in the price of apple?
Explanation
After a 10% increase the price is 1.1 times, and after a 10% decrease it is 1.1 × 0.9 = 0.99 times.
The price falls by 1%.
The price falls by 1%.
Question 10
In an election which contested was contested by 2 candidates, one candidate got 40% of total votes and yet lost by 1000 votes. What is the total number of votes casted in the election?
Explanation
One candidate got 40% of the votes, so the other got 60%. The difference = 60% - 40% = 20% of the total votes = 1000.
Total votes = 100020 × 100 = 5000.
Total votes = 100020 × 100 = 5000.
Question 11
If price of rice is 30% less than that of wheat, then price of wheat is how much per cent more than that of rice?
Explanation
The price of rice = 70% of the price of wheat = 0.7 × wheat.
The price of wheat is 10.7 = 1.4286 times the price of rice, so it is 42.86% more.
The price of wheat is 10.7 = 1.4286 times the price of rice, so it is 42.86% more.
Question 12
If 15% of Y is same as 21% of Z, then 12.5% of Y is equal to what per cent of Z?
Explanation
15% of Y = 21% of Z, so Y = 2115Z = 1.4Z.
12.5% of Y = 0.125 × 1.4Z = 0.175Z = 17.5% of Z.
12.5% of Y = 0.125 × 1.4Z = 0.175Z = 17.5% of Z.
Question 13
Y has to score 40% marks to pass. He gets 20 marks and fails by 40 marks. The maximum marks of the exam are?
Explanation
The pass mark = 20 + 40 = 60 marks, which is 40% of the maximum marks.
Maximum marks = 6040 × 100 = 150.
Maximum marks = 6040 × 100 = 150.
Question 14
56% of Y is 182. What is Y?
Explanation
56% of Y = 182, so Y = 18256 × 100 = 325.
Question 15
A fruit seller had some mangoes. He sells 30% mangoes and still has 280 mangoes. Find the number of mangoes he had.
Explanation
He sold 30%, so 70% of the mangoes remain = 280.
Total mangoes = 28070 × 100 = 400.
Total mangoes = 28070 × 100 = 400.
Question 16
The population of a city is 160,000. If it increases at the rate of 6% per annum, then what will be its population 2 years hence?
Explanation
Population after 2 years = 160,000 × (1.06)² = 160,000 × 1.1236 = 179,776.
Question 17
The number which exceeds 12% of it by 52.8 is:
Explanation
Let the number be x. x - 0.12x = 52.8, so 0.88x = 52.8 and x = 60.
Question 18
If the sales tax be reduced from 4 (13) % to 2 (12) %, then what difference does it make to a person who purchases a bag with marked price of Rs. 8000?
Explanation
The reduction in the sales tax rate = 413% - 212% = 133% - 52% = 116%.
The difference = 116 × 1100 × 8000 = Rs. 146.66.
The difference = 116 × 1100 × 8000 = Rs. 146.66.
Question 19
Evaluate :
28% of 400 + 45 % of 250
28% of 400 + 45 % of 250
Explanation
28% of 400 = 112 and 45% of 250 = 112.5.
Sum = 112 + 112.5 = 224.5.
Sum = 112 + 112.5 = 224.5.
Question 20
In a class, 20% of the students were absent for an exam. 30% failed by 20 marks and 10% just passed. Find the average score of the class if the remaining students scored an average of 65 marks and the cut off for passing the exam is 40.
Explanation
Take 100 students. 20 are absent (score 0). 30 failed by 20 marks, so they scored 40 - 20 = 20. 10 just passed with 40. The remaining 40 scored an average of 65.
Total = 0 + 30 × 20 + 10 × 40 + 40 × 65 = 600 + 400 + 2600 = 3600.
Average = 3600100 = 36.
Total = 0 + 30 × 20 + 10 × 40 + 40 × 65 = 600 + 400 + 2600 = 3600.
Average = 3600100 = 36.
Question 21
Find the number which is 60% less than 90.
Explanation
A number 60% less than 90 = 90 × (1 - 0.6) = 90 × 0.4 = 36.
Question 22
A vehicle has an insurance of 34 of its original value. Premium on the vehicle at the rate of 1.2% amounts to 720 Rs. What is the original value of the vehicle?
Explanation
The vehicle is insured for 34 of its value, and the premium at 1.2% is Rs. 720.
Insured value = 720 / 0.012 = Rs. 60,000, which is 34 of the original value.
Original value = 60,000 × 43 = Rs. 80,000.
Insured value = 720 / 0.012 = Rs. 60,000, which is 34 of the original value.
Original value = 60,000 × 43 = Rs. 80,000.
Question 23
While calculating the edge of a square, a worker makes an error of 2% in excess. What % error does he make in calculating area? (%)
Explanation
Let the actual edge be 100. The measured edge = 102.
Actual area = 10,000. Measured area = 102² = 10,404.
Error in area = 40410000 × 100 = 4.04%.
Actual area = 10,000. Measured area = 102² = 10,404.
Error in area = 40410000 × 100 = 4.04%.
Question 24
Income of A is 25% more than the income of B. What is the income of B in terms of income of A?
Explanation
Income of A = 1.25 × income of B, so B = 11.25 A = 0.8A.
B's income is 80% of A's income.
B's income is 80% of A's income.
Question 25
2 students gave an examination. One of them scored 9 marks more than other and his marks were 56% of the sum of total of both their marks. What are their individual marks?
Explanation
Let the lower score be x, so the higher score = x + 9.
The higher score is 56% of the total: x + 9 = 0.56(2x + 9) = 1.12x + 5.04, so 3.96 = 0.12x and x = 33.
The marks are 33 and 42.
The higher score is 56% of the total: x + 9 = 0.56(2x + 9) = 1.12x + 5.04, so 3.96 = 0.12x and x = 33.
The marks are 33 and 42.
Question 26
In a decade, a town’s population increases from 175000 to 262500. What is the average % increase of population each year?
Explanation
The population increases by 262500 - 175000 = 87500 in 10 years.
Percentage increase = 87500175000 × 100 = 50% in 10 years.
Average yearly increase = 5010 = 5%.
Percentage increase = 87500175000 × 100 = 50% in 10 years.
Average yearly increase = 5010 = 5%.
