The
instructions on a can of paint read that a half gallon of paint will
cover approximately 175 square feet. How many half gallon cans of
paint must be purchased to apply 2 coats of paint to cover 600 square
feet per coat?

**Solution:**

We
can think of this problems in terms of direct variation. The amount
of paint needed is directly proportional to the area that needs to be
painted.

Let

*y*= amount of paint in gallons*x*= area to be painted in square foot.

Therefore,
we use the equation for direction variation,

*y = kx.*
Substitute
½ for

*y*and 175 for*x*and solve for*k*.
½
=

*k*(175) (Divide both sides by 175)
1/350
=

*k*
To
apply 2 coats over 600 square feet means we need enough paint to
cover 1,200 square feet, therefore

*y*= (1/350)(1200)

*y*= 3.42 gallons.

We
need to purchase 7 cans of paint because 7(1/2) = 3.5.

## No comments:

## Post a Comment