Assume the length, breadth , height are 8x, 5x, 3x cm respectively.
Given: Volume of a cuboid is =3240 cubic cm.
(8x)(5x)(3x) = 3240
120 x3 = 3240
x3 = 3240/120 = 27
x = 3 cm
Hence the length, breadth , height are 24 cm, 15 cm, 9 cm respectively.