Heena invests an amount of $10250$ at $4$ $p.c.p.a.$ to obtain a total amount of $Rs. 12710$ on simple interest after a certain period. For how many years did she invest the amount to obtain the total sum?

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 ₹)?

Albert invested an amount of $x$ rupees in a fixed deposit scheme offering $10 \%$ per annum for the $1^{\text{st}}$ year and $15 \%$ per annum for the $2^{\text{nd}}$ year and received an amount of ₹ $20,240$ after two years. What is $x$ (in ₹)?

Nutan borrowed some money at a rate of $4$ $p.c.p.a.$ for the first $3$ years,at the rate of $8$ $p.c.p.a.$ for the next $2$ years,and at the rate of $9$ $p.c.p.a.$ for the period beyond $5$ years. If she paid a total $SI$ of $Rs. 19550$ at the end of $7$ years,how much money (in $Rs.$) did she borrow?

$A$ sum of money put at simple interest trebles itself in $15$ years. The rate per cent per annum is (in $\%$):

Manish borrowed a sum of $Rs. 1150$ from Anil at the simple rate of $6$ $p.c.p.a.$ for $3$ years. He then added some more money to the borrowed sum and lent it to Sunil for the same time at $9$ $p.c.p.a.$ at simple interest. If Manish gains $Rs. 274.95$ by way of interest on borrowed sum as well as his own amount from the whole transaction,then what is the sum (in $Rs.$) lent by him to Sunil?