To find out how many gallons of paint are used to paint each piece of furniture, we need to divide the total amount of paint used (4 gallons) by the total number of pieces of furniture (20 chairs + 5 small tables = 25 pieces).
Next, we divide the total amount of paint used (which is 4 gallons) by the number of pieces of furniture. So, 4 gallons of paint divided by 25 pieces of furniture gives us 4/25 = 0.16 gallons per piece of furniture.
Therefore, each chair and small table uses approximately 0.16 gallons of paint. I hope this helps!