Question regarding Solution

Question:

In a basket, there are a certain number of oranges and 3
3 apples. The probability of pulling two oranges out without replacement is 6 /11. What is the total number of pieces of fruit in the basket before any are removed?

My Question:

In the solution video to this question at minute 1:30, you say right hand side is bigger then the left hand side and therfore implies that “x is too small”. Where does this implication come from? Could you further explain the logic behind this systematic “Choosing numbers”?