The shelf is made of 3 pieces of wood, each 0.3 meter wide. there is also 0.05 meter of space between the shelf and the wall on each side. what is the width, in meters, of the closet? a. 0.4 b. 0.8 c. 1 d. 1.9

Since there are 2 sides to the shelf, there is 0.05*2=0.05+0.05=0.1 meters of space between the shelf and wall in total. Next, since each piece of wood is 0.3 meters wide and we have 3 of them, the total width of the wood is 0.3+0.3+<something>
Note that <width of wood>+<space between shelf and well> =width of closet
I challenge you to finish this on your own - good luck, and feel free to ask with any further questions!