Percentage Change Quiz

A number is first decreased by 5% and then increased by 5%. What will be the net increase or decrease?

• 0.25% increase

• 25% decrease

• 0.25% decrease

• No increase or decrease

Answer explanation

When a number is decreased by 5%, it becomes 95% of the original. Increasing this new value by 5% results in 95% * 1.05 = 99.75% of the original, leading to a net decrease of 0.25%.

If a number is increased by 20% and then it is decreased by 10%. Its net increase or decrease is:

• 8% increase

• 10% decrease

• 10 % increase

• 8% decrease

Answer explanation

Increasing a number by 20% gives 1.2x, and decreasing that result by 10% gives 1.2x * 0.9 = 1.08x. This is an 8% increase from the original number, confirming the correct answer is 8% increase.

The profit of a company increased by 10% from April to May, then it decreased by 20% from May to June and again increased by 50% from June to July. What was the % growth in profit from April to July?

• 15%

• 45%

• 32%

• 13%

Answer explanation

Let the profit in April be 100. After a 10% increase in May, it becomes 110. A 20% decrease in June brings it to 88. Finally, a 50% increase in July results in 132. The growth from April to July is (132-100)/100 * 100 = 32%.

The price of a book was first increased by 25% and then reduced by 20%. What is the change in its original price?

• 5% decrease

• No change

• 10% increase

• 10% decrease

Answer explanation

The book's price increases by 25%, then decreases by 20% of the new price. The final price is 100% of the original, resulting in no overall change in price.

If the consumption of sugar increases from 12 kg to 15 kg, then find the percentage growth.

• 39.2%

• 20%

• 25%

• 33.3%

Answer explanation

To find the percentage growth, use the formula: ((new value - old value) / old value) * 100. Here, ((15 kg - 12 kg) / 12 kg) * 100 = (3/12) * 100 = 25%. Thus, the correct answer is 25%.

The price of rice is increased from ` 25 per kg to ` 30 per kg. The consumption should be reduced to what percentage so that the expenditure remains the same?

• 2 16 % 3

• 1 8 % 3

• 10%

• 16%

Answer explanation

The price increase from `25 to `30 means a 20% increase. To keep expenditure constant, consumption must decrease by 20%. Thus, the required reduction in consumption is 16.67%, which rounds to 16%. Hence, the correct choice is 2 16 % 3.

When the price of a cycle decreased by 20%, then the number of selling of bicycles increased by 20%. What was the effect on sale of the shop?

• 4% decrease

• 4% increase

• 10% increase

• 10% decrease

Answer explanation

The price decrease of 20% leads to a 20% increase in sales volume. However, the revenue change is calculated as follows: Revenue = Price x Quantity. A 20% drop in price and a 20% rise in quantity results in a net 4% decrease in revenue.

How many % is the single discount equivalent to two consecutive discounts of 12% and 5%?

• 17%

• 8.5%

• 16.4%

• 15.2%

Answer explanation

To find the single discount equivalent to two consecutive discounts of 12% and 5%, use the formula: 1 - (1 - 0.12) * (1 - 0.05) = 1 - 0.88 * 0.95 = 1 - 0.836 = 0.164, or 16.4%. Thus, the correct answer is 16.4%.

The price of petrol has been increased by 10% in the new budget. The passenger of a motor vehicle can reduce the consumption to how many %, so that his total expenditure on petrol remains the same?

• 10%

• 1 9 % 11

• 11%

• 1 11 % 9

Answer explanation

To keep the total expenditure constant despite a 10% price increase, the passenger must reduce consumption by approximately 9.09%, which rounds to 9%. Thus, the correct choice is 1 9 % 11.

The salary of labour has been increased by 25%. The new salary should be decreased by which % so that the initial salary remains the same?

• 12%

• 15%

• 20%

• 10%

Answer explanation

If the salary is increased by 25%, the new salary is 1.25 times the original. To return to the original salary, we need to decrease the new salary by 20% (0.25/1.25 = 0.20). Thus, the correct answer is 20%.