Reverse Percentage

Reverse Percentage is the type of question which demand you to find the original number with these information:

→ The current value of the number

→ The decreased or increased

Example Number 1

A car is sold at a discount for 15% for 6800$. What is the price before the discount

→ In this question, it ask us to find the original number with the information:

The current value

The percentage decreased

To do this question, there are 2 steps:

Take 100% and minus it, then turn the answer into a decimal

Divide the decimal

→ 100% - 15% = 85%

→ 85% = 0.85

→ 6800 ÷ 0.85 =8000$

So 8,000$ is the price before the discount.

Example Number 2

The population of a town grew 5%, the population now is 403,200. What is the population before?

→ In this question, it ask us to find the original number with the information:

The current value

The percentage increased

To do this question there are 2 steps:

Take the increased percentage and add it with 100%, then turn it into a decimal

Take the current amount and divide it

→ 100% + 5% = 105%

→ 105% = 1.05

→ 403,200 ÷ 1.05 = 384,000

So the population before was 384,000.

Example Number 3

Money was put into a bank account, each year it gained interest by 60 percent! The current balance now is 560,000$, what was the balance before it gained interest?

What we would do first is add it with 100%

100% + 60% = 160%

Then turn it into a decimal

160% = 1.6

Then take the current number and divide the decimal

560,000 ÷ 1.6 = 350,000

Conclusion:

If going from a smaller to bigger number, take 100% and minus it. → Example Number 1.

If going from a bigger to a smaller number, add it with 100% → Example 2 and 3.

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