Three years ago, the population of a town was $50000$. If the annual increase during three successive years be at the rate of $5\%$, $4\%$ and $3\%$respectively, what is its present population?

The population of a city was $120000$ in the year $2013$. During next year it increased by $6\%$ but due to an epidemic it decreased by $5\%$in the following year. What was its population in the year $2015$?

The count of bacteria in a certain experiment was increasing at the rate of $2\%$ per hour. Find the bacteria at the end of $2$ hours if the count was initially $500000$.

The bacteria in a culture grows by $10\%$ in the first hour, decreases by $10\%$ in the second hour and again increases by $10\%$ in the third hour. Find the bacteria at the end of $3$ hours if the count was initially $20000$.

A machine is purchased for $₹625000$. Its value depreciates at the rate of $8\%$ per annum. What will be its value after$2$ years?

A scooter is bought at $₹$$56000$. Its value depreciates at the rate of $10\%$ per annum. What will be its value after $3$ years?

A car is purchased for $₹348000$. Its value depreciates at $10\%$ per annum during the first year and at $20\%$per annum during the second year. What will be its value after $2$ years?

The value of a machine depreciates at the rate of $10\%$ per annum. It was purchased $3$ years ago. If its present value is $₹291600$, for how much was it purchased?

Find the amount and the compound interest on $₹8000$ for $1$ year at $10\%$ per annum, compounded half-yearly.