Answer:
The correct answer is 9.
Explanation:
Let's start by analyzing the information we have.
We know that Takala put 9 marbles in the box, jackie put in 7, and laird put in 11.
Before continuing, the most convenient is to add these three things:
9 + 7 + 11 = 27.
We now know that those 27 were divided equally to each other, that is 27: 3.
So we just have to divide:
27: 3 = 9
In this way we can verify that each person obtained 9.