Mensuration - Quant/Math - CAT 2008

Question 4 the day: September 26, 2002
The question for the day is from the topic of Mensuration.

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

(1)

4%

(2)

300%

(3)

75%

(4)

400%

Solution:

Volume of 4 cm cube = 64 cc. When it is cut into 1 cm cube, the volume of each of the cubes = 1cc
Hence, there will be 64 such cubes. Surface area of small cubes = 6 (1²) = 6 sqcm.
Therefore, the surface area of 64 such cubes = 64 * 6 = 384 sqcm.
The surface area of the large cube = 6(4²) = 6*16 = 96.
% increase = = 300%