Answer:
2) 26
Explanation:
The first thing to paint is to divide it into three parts, like this:
1st part:
Room A can be painted orange, red or green.
Therefore, we have 3 ways to do it.
2nd part:
Room B can be painted orange, white or red.
Therefore, we have 3 ways to do it.
3rd part:
Room C can be painted white, red or green.
Therefore, we have 3 ways to do it.
To know the total number, each part must be multiplied, that is:
3 * 3 * 3 = 27
However, some of these 27 possible results break the condition that the 3 rooms cannot be painted the same color, that only happens when the three rooms are painted red.
Therefore, the number of times would be:
27 - 1 = 26