A carpenter is filling an open entranceway with a door and two side panels of the same width. The entranceway is 3 m wide. The door will be 1.2 m wide. How wide should the carpenter make the panels on either side of the door so that the two panels and the door will fill the entranceway exactly?

Solution:

The width of panels on either side is x

So

2x+1.2 = 3

x=0.9

So the width of panels on either side is 0.9m