Answer:
8 cubes are painted on 3 sides
24 cubes are painted on 2 sides
22 cubes are painted on 1 sides
6 cubes are painted on 0 side
E = 3 * 8/60 + 2 * 24/60 + 1 * 22/60 + 0 * 6/60 = 47/30 = 1.567
The prime factorisation of 81 is 3^4(because 3*3*3*3 four times =81)
do not change the rest 3^4 m^2 x^3