₹ $800$ at $5 \%$ per annum compound interest amounts to ₹ $882$ in how many years?

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

In how many years will a sum of ₹ $800$ at $10 \%$ per annum compounded semi-annually become ₹ $926.10$?

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 $Rs. 2000$.

$A$ sum of money doubles in $3$ years at compound interest,compounded annually. It will become $4$ times of itself in: (in $years$)

At what rate per cent per annum will ₹ $1000$ amount to ₹ $1331$ in $3$ years? The interest is compounded yearly.