The present value of an oil engine is Rs. 14,580. What was the worth of the engine 3 years before if the value depreciates at the rate of 10% every year?

In a Laboratory, the count of bacteria in a certain experiment was increasing at the rate of 2.5% per hour. Find the bacteria at the end of 2 hours if the count was initially 5,06,000.

From a village people started migrating to nearby cities due to unemployment problem. The population of the village two years ago was 6,000. The migration is taking place at the rate of 5% per annum. Find the present population.

The population of a village increases by 9% every year which is due to the job opportunities available in that village. If the present population of the village is11,881, what was the population two years ago?

Ponmani makes a fixed deposit of Rs. 25,000 in a bank for 2 years. If the rate of interest is 4% per annum, find the maturity value.