$A$ man buys a watch for ₹ $1950$ in cash and sells it for ₹ $2200$ at a credit of $1$ $year$. If the rate of interest is $10 \%$ $p.a.$,what is his profit or loss?

$A$ sum of money amounts to ₹ $9,800$ after $5$ $years$ and ₹ $12,005$ after $8$ $years$ at the same rate of simple interest. The rate of interest (in $\%$) per annum is

Mr. Thomas invested an amount of $Rs. 13,900$ divided in two different schemes $A$ and $B$ at the simple interest rate of $14 \%$ $p.a.$ and $11 \%$ $p.a.$ respectively. If the total amount of simple interest earned in $2$ $years$ be $Rs. 3508$,what was the amount (in $Rs.$) invested in Scheme $B$?

If the simple interest on a certain sum of money is $\frac{4}{25}$ of the sum and the rate per cent equals the number of years,then the rate of interest (in $\%$) per annum is

At what rate per cent per annum will the simple interest on a sum of money be $\frac{2}{5}$ of the principal in $10$ $years$?

Ravi invested a total amount of $Rs. 65,000$ in three different schemes $A, B, C$ with rates of interest $12\%$,$16\%$,and $18\%$ per annum respectively,and earned a total interest of $Rs. 10,180$ in one year. If the amount invested in scheme $A$ is $72\%$ of the amount invested in scheme $C$,then what was the amount (in $Rs.$) invested in scheme $B$ (in $,000$)?