First we need to calculate the volume of the cylinder
where
r=diameter/2=4/2=2 feet
h=6 feet
we substitute the values
then we have the next equivalence
1 cubic foot = 7.48 gallon
75.4 cubic feet= x
x is the number of gallon s for 75.5 cubic feet
a) It is almost the capacity of a fuel storage tank in the advertisement
b) the capacity of the advertisement is lower by 4 gallons than the cylindrical tank given