Find the amount directly using the formula $A=P\left(1+\frac{R\times T}{100}\right)$ if Principal $=P=₹450$, Rate $=7\%$ and Time $=5$ years.

Find the amount directly using the formula  $A=P\left(1+\frac{R\times T}{100}\right)$ if Principal $=₹3200$, Rate $=7.5\%$, Time $=2\frac{1}{2}$ years.

If the amount is $₹k$ by directly using the formula $A=P\left(1+\frac{R\times T}{100}\right)$ if Principal $=₹720$, Rate $=8.5\%$ per annum and Time $=3$ years, then find the value of $k$