RD Sharma Class 7 Solutions: Chapter 13: Simple Interest

The person who borrows money is called the borrower
The person who lends money is called the money lender
The money borrowed from a lender is called the principal
The additional money paid by the borrower to the lender for having used his money is called the interest.
Interest is said to be simple if it is calculated on the original principal throughout the loan period
In calculating the number of days, we do not count the day on which the money deposited but the date of withdrawal is counted

Number of Years = Number of days/365

If P = Prnicipal, R = Rate of interest per annum and T = Time, then the simple interest is given by S.I. = PRT / 100