$A$ 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

What annual instalment (in $Rs.$) will discharge a debt of $Rs. 1092$ due in $3$ years at $12 \%$ simple interest?

The rate of simple interest (in $\%$) for which a sum of money becomes $5$ times of itself in $8$ years is:

Arun invested a sum of money at a certain rate of simple interest for a period of $4$ years. Had he invested the same sum for a period of $6$ years,the total interest earned by him would have been $50$ percent more than the earlier interest amount. What was the rate of interest per cent per annum?

In how many years will ₹ $150$ produce the same interest at $8 \%$ per annum as ₹ $800$ produces in $3$ years at $4 \frac{1}{2} \%$ per annum?

$A$ sum of ₹ $7700$ is to be divided among three brothers Vikas,Vijay,and Viraj in such a way that the simple interest on each part at $5 \%$ $p.a.$ after $1, 2,$ and $3$ years,respectively,remains equal. The share (in ₹) of Vikas is more than that of Viraj by: