The formula for the volume of a cylinder is π × radius^2 × height. The π and height will remain the same, so the only difference will be in the radius. 6^2 = 36, and 3^2 = 9, so 9 is 1/4 of 36 (36 ÷ 4 = 9) which means that the answer is 1/4. I hope this helps!
