$A$ lent ₹ $5,000$ to $B$ for $2$ years and ₹ $3,000$ to $C$ for $4$ years on simple interest at the same rate of interest and received ₹ $2,200$ in all from both of them as interest. The rate of interest (in $\%$) per annum is:

Divide $Rs. 4758$ into three parts such that their amounts after $2, 3,$ and $4$ years respectively are equal,given the rate of interest is $5 \%$ per annum. Find the amount of the $1^{\text{st}}$ part (in $Rs.$).

An investor invested his savings in the stock market. The value of his investments increased by $12 \%$ and $9 \%$ in the first year and the second year respectively. If the value of his investments after two years became ₹ $97,664$,then how much had he invested (in ₹)?

Dalajit lent ₹ $10800$ to Jaabir for $3$ $years$ and ₹ $7500$ to Kabir for $2$ $years$ on simple interest and received ₹ $1422$ in all from both of them as interest. The rate of interest (in $\%$) per annum is

The population of a particular area of a city is $5000$. It increases by $10 \%$ in $1^{st} \,yr$. It decreases by $20 \%$ in the $2^{nd} \,yr$ because of some reason. In the $3^{rd} \,yr$ the population increases by $30 \%$. What will be the population of the area at the end of $3$ $years$?

$A$ certain sum is invested for $T$ years. It amounts to ₹ $400$ at $10 \%$ $p.a.$. But,when invested at $4 \%$ $p.a.$,it amounts to ₹ $200$. Find the time (in years) $(T)$.