$A$ sum of money at simple interest becomes four times in $24$ years. The rate per cent of interest per annum is

In what time will ₹ $8100$ produce the same income at $3 \%$ as ₹ $225$ in $4$ years at $3 \%$?

$A$ certain sum of money amounts to ₹ $918$ in $2$ $years$ and ₹ $969$ in $3.5$ $years$ at simple interest. What is the rate of interest (in $\%$ $p.a.$)?

For what sum (in ₹) will the simple interest at $R \%$ per annum for $2$ years be $R$?

$A$ 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:

An automobile financier claims to be lending money at simple interest,but he includes the interest every six months for calculating the principal. If he is charging an interest of $10 \%$ per annum,the effective rate of interest (in $\%$) becomes: