What is difference between $C.I.$ and $S.I.$ of $Rs. 12000$ on $5 \%$ per annum for $2$ years?

Sonika invested an amount of ₹ $5800$ for $2$ years. At what rate of compound interest (In $\% p.a.$) will she get an amount of ₹ $594.50$ at the end of two years?

Suneeta borrowed certain sum from Reena for $2 \,yr$ at simple interest. Suneeta lent this sum to Venu at the same rate for $2 \,yr$ at compound interest. At the end of $2 \,yr$, she received $Rs. 110$ as compound interest but paid $Rs. 100$ as simple interest. Find the sum and the rate of interest?

A sum of money placed at compound interest doubles itself in $4$ $years$. In how many $years$ will it amount to four times itself?

Aditya invest $Rs. 50,000$ in a fixed deposit at $10 \%$ $C.I.$ for $2$ years. At the end of $2$ years she put the money in another deposit at $12 \%$ $S.I.$ for $3$ years. What was the final value (In $Rs.$)  of the initial Investment?

If the compound interest on a sum for $2$ years at $12 \frac{1}{2} \%$ per cent is ₹ $510$, the simple interest (In ₹) on the same sum at the same rate for same period of time is