The diameters of two-cylinder are in the ratio 2 : 3 so the radius of the cylinders are also 2:3.
Assume that radius of first cylinder is 2r and second cylinder be 3r.
Assume that height of first cylinder is 5h and second cylinder be 4h.
Volume of the first cylinder = πr2h
= π × 2r × 2r × 5h = 20 πr2
Volume of the second cylinder = πr2h
= π × 3r × 3r × 4h = 36 πr2 h
Ratio between volumes
= 20πr2 h : 36πr2 h = 20 : 36 = 5 : 9
Volume of the first cylinder is 400.
If the volume of second cylinder be x, then
5 : 9 = 400: x; 5x = 400 × 9
x = \(\frac{400\times9}{5}\) = 80 × 9 = 720 cm3
