Class 8 Chapter 9: Applications of Percentages

Important Concepts and Formulas on Applications of Percentages

1.    Per cent means per hundred or for every hundred.

2.    The numerator of a fraction with denominator 100 represents percentage.

3.    To convert a fraction into a per cent, multiply the fraction by 100.

4.      To convert a ratio into a per cent, write it as fraction and multiply it by 100.

5.      To convert a decimal into a per cent, shift the decimal point two places to the right.

6.      To convert a per cent into a fraction, divide it by 100 after removing the symbol of %.

7.      Increase = Increased value – Original value.

8.      Percentage increase = (Increase/Original value) × 100% and increased value = (100% + increase %) × original value.

9.      Decrease = Original value – Decreased value.

10. Percentage decrease = (Decrease/Original value) × 100% and decreased value = (100% – decrease %) × original value.

11. Discount = Marked price – Selling price.

12. Percentage discount = (Discount/Marked price) × 100%.

13. Selling price = Marked price × (100% – Percentage discount).

14. GST stands for Goods and Services Tax.

15. GST = Price before GST × GST rate.

16. Price after GST = Price before GST × (100% + GST rate).