$A$ 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

$A$ lends ₹ $2500$ to $B$ and a certain sum to $C$ at the same time at $7 \%$ $p.a.$ simple interest. If after $4$ $years,$ $A$ altogether receives ₹ $1120$ as interest from $B$ and $C,$ then the sum lent (in ₹) to $C$ is

Hemant makes a fixed deposit of $Rs. 20000$ in Bank of India for a period of $3 \,yr$. If the rate of interest is $13 \%$ $SI$ per annum charged half-yearly,what amount (in $Rs.$) will he get after $42 \,months$?

Rashmi lent $Rs. 600$ to Geeta for $2 \,yr$ and $Rs. 150$ to Seeta for $4 \,yr$ at the same rate of interest and received altogether $Rs. 80$ as simple interest from both. Find the rate of interest (in $\%$).

The rate of interest for the first $2$ years is $3 \%$ per annum,for the next $3$ years is $8 \%$ per annum,and for the period beyond $5$ years is $10 \%$ per annum. If a man gets $Rs. 1520$ as simple interest for $6$ years,how much money (in $Rs.$) did he deposit?

In what time (in $years$) will ₹ $1200$ become ₹ $1344$ at $6 \%$ per annum simple interest?