The population of a country is $10$ crore and it is expected that the population will become $13.31$ crore in $3$ years. What will be the annual growth rate in percent?

The difference between $C.I.$ and $S.I.$ on $Rs. 700$ in $2$ years at $5 \%$ per annum is (in $Rs.$):

$A$ sum of money at compound interest amounts to thrice itself in $3$ years. In how many years will it be $9$ times itself?

The simple interest on a sum of money for $3$ years is ₹ $240$ and the compound interest on the same sum,at the same rate for $2$ years is ₹ $170$. The rate of interest is (in $\%$):

$A$ man gave $50 \%$ of his savings of ₹ $84,100$ to his wife and divided the remaining sum among his two sons $A$ and $B$ of $15$ and $13$ years of age respectively. He divided it in such a way that each of his sons,when they attain the age of $18$ years,would receive the same amount at $5 \%$ compound interest per annum. The share of $B$ was (in ₹):

$A$ sum of money,deposited at some rate $p.c.p.a.$ of compound interest,doubles itself in $4$ years. In how many years will it become $16$ times of itself at the same rate?