Suppose the bottom area of the graph 1 is a and the capacity = a * h.

The capacity of the cylinder in figure 2 is 4 * a * ha * h.

The height of the cylinder in Figure 2 should be h, right?

Figure 2 shows16 * a * h.

* * * Need (16Ah+4Ah)/Ah=20 times.

If that cylinder of fig. 2 is high h,

It only needs 4 ah/ah+16 ah/ah = 4+16 (h/h) times.