If ₹ $500$ amounts to ₹ $725$ at $9 \%$ simple interest in some time,what will ₹ $600$ amount (in ₹) to at $11 \%$ in the same time?

$A$ sum of money becomes $\frac{8}{5}$ of itself in $5$ $years$ at a certain rate of interest. The rate per cent per annum is

$A$ certain sum is invested for $T$ years. It amounts to ₹ $400$ at $10 \%$ $p.a.$. But,when invested at $4 \%$ $p.a.$,it amounts to ₹ $200$. Find the time (in years) $(T)$.

Nitin borrowed some money at the rate of $6 \% \text{ p.a.}$ for the first three years,$9 \% \text{ p.a.}$ for the next five years,and $13 \% \text{ p.a.}$ for the period beyond eight years. If the total interest paid by him at the end of eleven years is ₹ $8,160$,the money borrowed by him was:

$A$ certain sum of money amounts to ₹ $2200$ at $5 \%$ $p.a.$ rate of interest,and ₹ $2320$ at $8 \%$ interest in the same period of time. The period of time (in years) is:

What principal will amount (in ₹) to ₹ $15000$ at $10 \%$ per annum in $5$ years?