If $64000$ is deposited at $5 \%$ compound interest for a period of $18$ months,interest being compounded half-yearly,find the amount.

Raghu invested a certain sum in Scheme $X$ for $4$ years. Scheme $X$ offers simple interest at $12\%$ per annum for the first two years and compound interest (compounded annually) at $20\%$ per annum for the next two years. The total interest earned by him after $4$ years is $₹ 11016$. What was the sum (in $₹$) invested by Raghu in Scheme $X$?

What will be the compound interest (in ₹) on a sum of ₹ $1875$ after $2$ years if the rate of interest for the first year is $4 \%$ and that for the second year is $8 \%$?

Which of the statements given below are sufficient to answer the following question?
What is the rate of interest per annum on an investment of $Rs. 800$?
$(I)$ The income from $S.I.$ at the end of $3$ years at the same rate of interest is $19$.
$(II)$ $C.I.$ is $15.76$ more than $S.I.$ on the same sum and same rate in $2$ years.

$A$ sum of money lent at compound interest for $2 \, yr$ at $20 \% \, p.a.$ would fetch $Rs. 964$ more,if the interest was payable half-yearly than if it was payable annually. What is the sum (in $Rs.$)?

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