$A$ certain sum becomes ₹ $1020$ in $5$ years and ₹ $1200$ in $8$ years at simple interest. What is the value of Principal (in ₹)?

Suhit borrowed a sum of $Rs. 6300$ from Vikas at the rate of $14 \%$ per annum for $3$ years. He then added some more money to the borrowed sum and lent it to Mohit at the rate of $16 \%$ simple interest for the same time. If Suhit gained $Rs. 618$ in the whole transaction,what sum did he lend (in $Rs.$) to Mohit?

$A$ sum of money lent out at simple interest amounts to ₹ $720$ after $2$ $years$ and to ₹ $1,020$ after a further period of $5$ $years$. The sum is (In ₹)

$₹ 800$ becomes $₹ 956$ in $3$ years at a certain rate of simple interest. If the rate of interest is increased by $4 \%$,what amount (in $₹$) will $₹ 800$ become in $3$ years?

$A$ sum of ₹ $25400$ was lent out in two parts,one at $12 \%$ and the other at $12 \frac{1}{2} \%$. If the total annual income is ₹ $3124.2$,the money lent at $12 \%$ is (in ₹):

An investor invested his savings in the stock market. The value of his investments increased by $12 \%$ and $9 \%$ in the first year and the second year respectively. If the value of his investments after two years became ₹ $97,664$,then how much had he invested (in ₹)?