Question

The coach of a cricket team buys 3 bats and 6 balls for Rs 3900. Later, she buys another bat and 3 more balls of the same kind for Rs 1300. Represent this situation algebraically and geometrically.

Answer 1

Let cost of one bat = Rs x

Cost of one ball = Rs y

3 bats and 6 balls for Rs 3900 So that

3x + 6y = 3900 

Dividing equation by 3, we get

x + 3y = 1300

Graphical representation:

we have,

3x + 6y = 3900

3(x + 2y) = 3900

x + 2y = 1300

a = 1300 - 2y

Thus, we have following table:

x	1300	500	700	100
y	0	400	300	600

we have, x + 3y = 1300

x = 1300 - 3y

Thus, we have following table:

x	1300	100	400	1000
y	0	400	300	100

when we plot the graph of equations, we find that both the lines intersect at the point (1300, 0). 

Therefore, a = 1300, y = 0 is the solution of the given system of equations.