A machine is depreciated at the rate of 10 % yearly and the ultimate scrap value was ₹ 6561. Find the effective life of the machine. The price of the machine is ₹ 10,000.

Find the time required to spent and energy of 100 J by a machine of power 10 W?

Price of petrol increased by 10% last year. Now the prices are reduced by 10% Find the net increase or decrease in the price of petrol.

A scooter was bought at Rs 42,000. Its value depreciated at the rate of 8% per annum. Find its value after one year.

A manufacturer instals a machine at a cost of $ 3,000. At the end of 9 years, the machine has a value of $ 1200. Assuming the yearly depreciation to be a constant amount, find its price after 13 years

A machinerty worth Rs.10,500 depreciated by 5% .Find its value after one year.

A factory makes tennis rackets and cricket bats. A tennis racket takes 1.5 hours of machine time and 3 hours of craftman’s time in its making while a cricket bat takes 3 hour of machine time and 1 hour of craftman’s time. In a day, the factory has the availability of not more than 42 hours of machine time and 24 hours of craftsman’s time. If the profit on a racket and on a bat is Rs 20 and Rs 10 respectively, find the maximum profit of the factory when it works at full capacity.

First order reaction is found to have rate constant, k= 5.5xx 10^(-14) s^-1 . Find the half life to the reaction.