Question

A cube is divided into 343 identical cubelets. Each cut is made parallel to some surface of the cube. But before donig that cube is coloured with green colour on one set of adjacent faces, red on the second, and blue on the third set.

How many minimum cuts you have made?

• A. 15
• B. 18
• C. 21
• D. 9

Answer 1

The correct option is B 18

$n^3=343=7^3\Rightarrow n=7$

Minimum number of cuts = 3(n-1)

=3(7-1) =3$\times$ 3$\times$6=18



As we can see in above figure. 3 faces are visible in 3-diff colours, out of hidden faces, bottom is red, one is green and another is blue.