An amount fetched a total simple interest of ₹ $3200$ at the rate of $6.25 \%$ per year in $4$ years. What is the amount (principal) in ₹?

The simple interest on a sum of money will be ₹ $600$ after $10$ $years$. If the principal is trebled after $5$ $years$,then what will be the total interest (in ₹) at the end of the tenth year?

Mr. Irani borrowed a sum of ₹ $10000$ from a finance company for $6$ years at $8 \%$ per annum. The amount (in ₹) returned by Mr. Irani to the finance company is:

$A$ certain sum of money amounts to ₹ $2200$ at $5 \%$ $p.a.$ rate of interest,and ₹ $2320$ at $8 \%$ interest in the same period of time. The period of time (in years) is:

Nutan borrowed some money at a rate of $4$ $p.c.p.a.$ for the first $3$ years,at the rate of $8$ $p.c.p.a.$ for the next $2$ years,and at the rate of $9$ $p.c.p.a.$ for the period beyond $5$ years. If she paid a total $SI$ of $Rs. 19550$ at the end of $7$ years,how much money (in $Rs.$) did she borrow?

The simple interest on ₹ $500$ at $6 \%$ per annum from $May$ $3^{rd}$ to $July$ $15^{th}$ in the same year is (in ₹):