What would be the compound interest (in $Rs.$) accrued on an amount of $Rs. 7850$ at the rate of $14$ $p.c.p.a.$ in $2$ years?

Which information given below is sufficient to know the principal amount if the difference between the $C.I.$ and $S.I.$ for $2$ years is $18$?
$(I)$ The rate is same at which an amount of $Rs. 1000$ becomes $1120$ in $2$ years under $S.I.$
$(II)$ The principal is $Rs. 2000$.

The difference between compound interest and simple interest on a sum for $2$ years at $10 \%$ per annum,when the interest is compounded annually,is ₹ $20$. If the interest were compounded half-yearly,the difference in the two interests (in ₹) will be:

$A$ certain sum will amount to ₹ $12,100$ in $2$ years at $10 \%$ per annum of compound interest,interest being compounded annually. The sum is (In ₹)

$A$ certain sum at compound interest amounts in two years to ₹ $2809$ and in three years to ₹ $2977.54$. Find the rate of interest and the original sum (in ₹).

Sita deposited $Rs. 5000$ at $10\%$ simple interest for $2$ years. How much more money (in $Rs.$) will Sita have in her account at the end of $2$ years,if it is compounded semi-annually?