You need to notice that the problem provides the capacity and the height using different units of measure, hence, you need to use the same units of measure, thus, you need to convert the liters into cubice meters such that:

`50 liters = 0.05 m^3`

Since the shape of container is cylindrical, you need to use the following formula of volume such that:

`V = pi*r^2*h`

r represents the radius of cylinder

h represents the height of cylinder

`0.05 = pi*r^2*0.7 => r^2 = 0.05/(pi*0.7) => r = sqrt(0.05/(pi*0.7)) => r~~0.388`

You need to find the diameter such that:

`D = 2*r => D = 0.776 m`

**Hence, evaluating the diameter of container yields `D ~~ 0.78 ` meters.**