Area of the square = 1 2 × d i a g o n a l 2=  1/2 * 3.8 * 3.8 = 7.22 sq.m

The maximum area of the triangle will come when the given sides are placed at right angles. If we take 8 as the base and 5 as the height the area = ½ x 8 x 5=20

v 1 v 2 = r 1 2 × h 1 r 2 2 × h 2 

d1 =  2 r 1 and d2 =  2 r 2 are diameters

surface area of a cube= 6 x (8 x 8) = 384 sq.ft  

quantity of paint required=(384/16)=24kg  

cost of painting= 36.5 x 24 = Rs.876

Volume of cuboid = (24 x 9 x 8) cm = 1728 cu.cm
Volume of small cube = (3 x 3 x 3) cm = 27 cu.cm

So, No. of small cubes formed = 1728/27 = 64.