Question

A cylindrical tank is half-full of oil. The cylinder has a base radius of 100 cm. The height of the cylinder is 250 cm. How many litres of oil are in the tank? 1 litre = 1000 cm3

Answer 1

V=hpir²


1/2 full

Vcylinderthisone=(1/2)hpir^2
given
h=250
r=100

so

V=(1/2)(250)pi(100)²
V=125pi10000
V=1250000pi
aprox pi=3.141592
V=3926990 cm^3

divide by 1000
3926.99 liters
about 3927 liters

Answer 2

V=πr²h
V=π(100)² x 250
V=7853982.5 cm³

Then do the conversion:
1 litre = 1000 cm³
x litre =  7853982.5

Cross multiply:

1000x= 7853982.5
 x= 7853982.5/1000
x= 7853.98 litres