72"X18"x8"=10368 cubic inches 10368 cu in x 0.00433 cubic inches/gal = 44.9 gallons Answer: 44.9 gallons
24'x18'x21' is 9,072 cubic feet which converts to 67,863.27 US gallons.
(13X12)X(5X12)X18=168,480 inches^3; 1 Gallon = 231 inches^3 168,480/231 = 729.4 gallons
√x19 = (√x18)(√x) = x9√xBecause:√x18 = x18/2 = x9
There are many places where one can purchase a X18 Pocket Bike. One can purchase an X18 Pocket Bike at popular on the web sources such as USA Pocket Bikes and Mini Pocket Rockets.
Since they can grow to 18 inches - you'd need a vivarium measuring a minimum of 36 x18 x 18 inches.
if those measurements are in inches then that equals 18 cubic feet x 7.48 gallons per cubic foot = 134.64 gallons