$A$ sum was doubled with $12 \frac{1}{2} \%$ rate of simple interest per annum. The time taken (in years) for that sum is:

Prakash lends a part of ₹ $20,000$ at $8 \%$ simple interest and the remaining at $\frac{4}{3} \%$ simple interest. His total income after a year was ₹ $800$. Find the sum (in ₹) lent at $8 \%$ interest.

If the interest on ₹ $800$ is more than the interest on ₹ $400$ by ₹ $40$ in $2$ years,then the rate of interest (in $\%$) per annum is:

If a sum of money doubles itself in $8$ years at $S.I.$,then the rate of interest per annum (in $\%$) is: (in $.5$)

Prabhat took a certain amount as a loan from a bank at the rate of $8 \%$ simple interest per annum and gave the same amount to Ashish as a loan at the rate of $12 \%$ per annum on simple interest. If at the end of $12$ years,he made a profit of $Rs. 320$ in the deal,what was the original amount (in $Rs.$)?

$A$ took two loans altogether of ₹ $1200$ from $B$ and $C$. $B$ claimed $14 \%$ simple interest per annum,while $C$ claimed $15 \%$ per annum. The total interest paid by $A$ in one year was ₹ $172$. How much did $A$ borrow from $B$?