Question

how will be surface area of a cube change of its length of its edge halved and doubled.

Answer 1

it will be its four times

Answer 2

If Halved :
T.S.A. = 6$a^{2}/2$
=6$a^{2}/4$ 
The area will be reduced 4 times
If doubled :
T.S.A. =6$2a^{2}$
=6$4a^{2}$
The area will be increased by 4 times