To find out how much paint Mr. Savage will need to cover 1,800 square feet, we first need to determine the paint coverage rate per square foot.
We know that 3 gallons of paint cover 1,350 square feet. Therefore, the coverage rate is:
\[ \text{Coverage rate} = \frac{3 \text{ gallons}}{1,350 \text{ square feet}} = \frac{3}{1350} \text{ gallons per square foot} = \frac{1}{450} \text{ gallons per square foot} \]
Next, we calculate how much paint will be needed for 1,800 square feet using the coverage rate:
\[ \text{Paint needed} = 1,800 \text{ square feet} \times \frac{1}{450} \text{ gallons per square foot} \]
Calculating this gives:
\[ \text{Paint needed} = \frac{1,800}{450} = 4 \text{ gallons} \]
Thus, Mr. Savage will need 4 gallons of paint to cover 1,800 square feet.