The least number of completed years in which a sum of money put out at $20 \%$ $C.I.$ will be more than doubled is

$A$ sum of money amounts to ₹ $6655$ at the rate of $10 \%$ compounded annually for $3$ years. The sum of money is (in ₹):

If the rate of interest is $4 \%$ per annum for the first year,$5 \%$ per annum for the second year,and $6 \%$ per annum for the third year,then the compound interest on $Rs. 10000$ for $3$ years will be (in $Rs.$):

Abhinav invested a certain amount at the rate of $8$ $p.c.p.a.$ for $5$ years and obtained a $SI$ of $Rs. 3800$. Had he invested the same amount at the same interest rate for $2$ years,how much amount (in $Rs.$) would he have obtained as $CI$ at the end of $2$ years?

The difference of compound interest (in ₹) on ₹ $800$ for $1$ year at $20 \%$ per annum when compounded half-yearly and quarterly is:

What will be the difference between simple and compound interest (in ₹) at $10 \%$ per annum on a sum of ₹ $1000$ after $4$ years?