# Simple Interest - Facts and Formulae

## 1. Principal :The money borrowed or lent out for a certain period is called the principal or the sum.

## 2. Interest :Extra money paid for using other’s money is called interest.

## 3. Simple Interest (S.I.) :If the interest on a sum borrowed for certain period is reckoned uniformly, then it is called simple interest.

## Let the principal = P, Rate = R% per annum (p.a) and Time = T years. Then ,

## 1. S.I. = (P x R x T )/ 100)

## 2. P = (100 x S.I.) / R x T)

## 3. R = (100 x S.I) / P x T)

## 4. T = (100 x S.I.) / P x R)