A cylindrical rain barrel with a diameter of 2.5 feet and a height of 3.5 feet is filled to a height of 1.5 feet. How many more gallons of water can the barrel hold? Round your answer to the nearest whole number. (1ft cubed is about 7.5 gallons)

The formula for solving the volume of a tank is V=pi*r²*h where "r" represent the radius and "h" for the height.

In the given problem we need to solve for the volumes,

V=3.1416*r²*h

r=diameter/2

r=2.5/2

r=1.25

h=3.5-1.5 since 1.5 is already filled with water

h=2

V=3.1416*1.25²*2

V=9.8175 ft³

Solving for how many more gallons (1 cubic feet is 7.5 gallons)

# of gallons=9.8175 * 7.5/1

# of gallons=73.63 gallons