Please solve Q.No.8

Dear student, 
Given that side of a big cube = 4 cm 
Volume of a big cube = 4 x 4 x4 = 64 cm³ . 
Total surface area of big cube = 6 x 4 x 4 = 96 cm².
Each side of a small cube = 1 cm  
Volume of a small cube = 1 x1 x1 = 1 cm³ 
Total Surface Area of small cube = 6 x 1 x 1 = 6 cm² 
Number of new cubes = 64 / 1 = 64 
∴ Total Surface Area of all small cubes = 64 x 6 = 384 cm^{2
So,  change in percentage = (384 - 96)*100/96
        .: Increase in percentage = 75%
Regards.}