# Graph of Simple Interest vs. Number of Years

Here we will learn about the graph of simple interest vs. number of years.

Simple interest on a certain sum is \$ 40 per year.

Then, S = 40 × x, where x is the number of years.

1. Draw a graph of the above function.

2. From the graph find the value of 5, when
(a) x = 5        (b) x = 6

Solution:

1. The given function is S = 40 × x.

Putting x = 1, 2, 3, 4 successively and getting the corresponding value of S. we get the table given below.

       x 1 2 3 4 S = 40 × x 40 80 120 160

Along the x-axis: Take 1 small square = 1 unit.

Along the y-axis: Take 1 small square = 10 units.

Now, on a graph paper, plot the points

A (1, 40), B (2, 80), C (3, 120) and D (4, 160).

Join them successively to get the required graph line, shown below.

2. Reading off from the graph of simple interest vs. number of years:

(a) On the x-axis, take the point L at x = 5.

Draw LP ⊥ x-axis, meeting the graph at P.

Clearly, PL, = 200 units.

Therefore, x = 5 ⇒ S = 200.

Thus, when x = 5, then S = 200.

(b) On the x-axis, take the point M at x = 6.

Draw QM ⊥ x-axis, meeting the graph at Q.

Clearly, QM = 240 units.

Therefore, x = 6 ⇒ S = 240.

Thus, when x = 6, then S = 240.

Related Concepts:

Coordinate Graph

Signs of Coordinates

Find the Coordinates of a Point

Coordinates of a Point in a Plane

Plot Points on Co-ordinate Graph

Graph of Linear Equation

Simultaneous Equations Graphically

Graphs of Simple Function

Graph of Perimeter vs. Length of the Side of a Square

Graph of Area vs. Side of a Square

Graph of Distance vs. Time