$A$ certain amount earns simple interest of ₹ $1,750$ after $7$ years. Had the interest rate been $2 \%$ more per annum,how much more interest would it have earned (in ₹)?

The simple interest on a sum for $8$ years is ₹ $47500$. The rate of interest is $10 \%$ per annum for the first $5$ years and $15 \%$ per annum for the next $3$ years. What is the value (in ₹) of the sum?

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 $,000$)?

$A$ man invests a certain sum of money at $6 \%$ $p.a.$ simple interest and another sum at $7 \%$ $p.a.$ simple interest. His income from interest after $2$ $years$ was $Rs. 354$. One-fourth of the first sum is equal to one-fifth of the second sum. Find the total sum (in $Rs.$) he invested.

What sum lent at $10 \%$ per year on $S.I.$ will amount to $Rs. 450$ in $2$ years?

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