1. To calculate the volume of the pool you need to convert the length, width and height into one same unit. The volume would be:
volume= length * width * height
volume= 50m *25m *(48ft *0.3048m)= 18288m^3
volume in gallons= 18288m^3 * (264.172 gallons/m^3)= 483.118 gallons
2. The mass would be found by multiplying density with volume. You will need to some unit conversion to get the mass in kilogram. Remember that 1g= 1000kg and 1m^3= 1,000,000ml
mass= volume * density
mass= 18288m^3 * (10^6 ml^3/m^3) * 1.0 g/mL / (1000g/kg)= 18,288,000 kg
