The compound interest (in ₹) on ₹ $12000$ for $9$ months at $20 \%$ per annum,interest being compounded quarterly,is

If the difference between the $C.I.$ compounded half-yearly and simple interest on a sum at $10 \%$ per annum for one year is $Rs. 25$,the sum (in $Rs.$) is:

If the ratio of $C.I.$ and $S.I.$ interest for the same principal and rate of interest for $2$ years is $1.2,$ find the rate of interest (in $\%$).

Find the least number of complete years in which a sum of money put out at $20 \%$ compound interest will be more than double?

What will be the amount (in ₹) if a sum of ₹ $5000$ is placed at compound interest for $3$ years,while the rate of interest for the first,second,and third years is $2\%$,$3\%$,and $4\%$ per annum,respectively?

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: