Simple interest on a certain sum is $\frac{16}{25}$ of the sum. If the rate per cent and time (in years) are equal,then the rate per cent is:

Asmita invests an amount of $Rs. 9535$ at the rate of $4\%$ per annum to obtain a total amount of $Rs. 11442$ on simple interest after a certain period. For how many years did she invest the amount to obtain the total sum?

$A$ 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 $\%$ $p.a.$)?

If the simple interest on a certain sum of money is ₹ $256$ and the rate of interest per annum equals the number of years,then the rate of interest (in $\%$) is:

Arun lends ₹ $20,000$ to two of his friends. He gives ₹ $12,000$ to the first at $8 \%$ p.a. simple interest. Arun wants to make a profit of $10 \%$ on the whole. The simple interest rate $\%$ at which he should lend the remaining sum of money to the second friend is

Gaurav borrowed $Rs. 800$ at $6 \%$ and Naresh borrowed $Rs. 600$ at $10 \%$. After how much time will they both have equal debts?