‘Per cent’ means ‘per hundred’. It is given by % symbol. Here x% means x per hundred . Thus, any percentage can be converted into an equivalent fraction by dividing it by 100.

Also, any fraction or decimal can be converted into its equivalent percentage by multiplying with 100.
eg

Important Formulae

3. If the price of the commodity increases by r% then the reduction in consumption so as not to increase the expenditure is

4. If the price of the commodity decreases by r% then the reduction in consumption so as not to increase the expenditure is