Find the difference between $C.I.$ and $S.I.$ on $Rs. 15000$ at $3 \%$ per annum for $3$ years.

The compound interest on a certain sum of money for $2$ years at $5 \%$ per annum is ₹ $410$. The simple interest (in ₹) on the same sum at the same rate and for the same time is:

Mr. Dua invested money in two schemes $A$ and $B$ offering compound interest at $8 \%$ per annum and $9 \%$ per annum respectively. If the total amount of interest accrued through two schemes together in two years was ₹ $4818.30$ and the total amount invested was ₹ $27000$. What was the amount (in ₹) invested in scheme $A$?

₹ $6,100$ was partly invested in Scheme $A$ at $10 \%$ p.a. compound interest (compounded annually) for $2$ years and partly in Scheme $B$ at $10 \%$ p.a. simple interest for $4$ years. Both the schemes pay equal interests. How much was invested (in ₹) in Scheme $A$?

The difference of compound interest (in ₹) on ₹ $800$ for $1$ year at $20 \%$ per annum when compounded half-yearly and quarterly is:

What annual payment (in ₹) will discharge a debt of ₹ $1025$ due in $2$ years at the rate of $5 \%$ compound interest?