A 4 cm cube is cut into 1cm cubes. What is the percentage increase in the surface area after such cutting?

Initial surface area of the cube = 6$$(side)^2$$ 

= 6$$(4)^2$$ 

= 96$$cm^2$$

No. of new cubes = $$\ \ \frac{\ Volume\ of\ older\ cube}{Volume\ of\ 1\ new\ cube}$$

=$$\ \ \frac{\ 4\times\ 4\times\ 4}{1\times\ 1\times\ 1}$$

=64 cubes 

Newer surface area of 64 cubes = 64*6$$(1)^2$$ = 384$$cm^2$$

Percentage increase in surface area = $$\ \ \frac{384-96}{96}$$ *100

=$$\ \ \frac{28800}{96}$$

 = 300%

B is the correct answer