Question

I am planning to tile my floor. Each tile is square and has a design which is a 3x3 grid of
squares. I want to use a combination of 4 different types of tile and when I have finished I want
to have used the same number of each tile. I also want the proportion of squares of each colour
to be equal.

Which one of the following 5 tiles should I not choose?

The link to the questions is: question 12
http://www.admissionstestingservice.org/images/20356-past-paper-2010-section-1.pdf

Urgent help needed thanks.

Answer 1

Consider the situation where you don't include tile E. 5 black, 4 grey. 0 white. Make a quick table of what you have left
B G W\[\left[\begin{matrix}2&4&3\\1& 2&6\\3&2&4\\4&2&3\end{matrix}\right]\]total
\[\left[\begin{matrix}10&10&16\end{matrix}\right]\]Ten black, ten grey, sixteen white is not equal proportions so E is not the right answer.
Repeat this for all other combinations.