## What is Per annul means ?

**Per annul means For a year.**

P = Principle

R = Rate of per annul

T = Number of years

When we Add Simple Interest into Principle. It becomes into Amount.

**Formulas Need to Remember**

**S.I** **=( P X R X T / 100 )**

Here, P = Principle.

R = Rate per annul.

T = Number of years.

**Formula:**

In case** S.I ( Simple Interest )**, **T ( Number of years )** and **R (Rate per annul )** are given in Question then we can easily find the **Principle or Sum**.

**P = ( S.I X 100 / R X T ).**

**Formula:**

In case **S.I ( Simple Interest ),** **T ( Number of years )** and **P ( Principle )** are given in question then we can easily find the** R (Rate per annul ).**

**R** = ( S.I X 100 / P X T ).

**Example 1:**

Find the simple interest on Rs 500 for 5 years at 5 per cent ?

**Answer :**

SI = 500 x 5 x 5 / 100

Simple interest in 5 years is Rs 125.