As a result of continuous publicity on harmful reactions in the use of cold drinks filled, bottles, the number of users of cold drinks is decreased by 25% every year in comparison to its previous year. 3 years before number of users of cold drink in a town was 80000. Let us write by calculating, the number of users of cold drink in the present year.

The price of a machine of a factory is ₹18000. The price of that machine decreases by 10% in each year. Let us calculate its price after 3 years.

For the families having no electricity in their house, a Panchayat samity of village Bakultala accepted a plan to offer electric connections. 1200 families in this village have no electric connection in their house. In comparision to its previous year, it is possible to arrange electricity every for 75% of the families having no electricity, let us write by calculating, the number of families without electricity after 2 years.

As a result of publicity on smoking, the number of smoker is decreased by % every year in comparison to its previous year. If the number of smokers at present in a city is 33750, let us write by calculating, the number of smoker in the city 3 years before.

In case of compound interest, the rate of compound interest per annum is-