To determine how many snow globe kits come in each box, we start by setting up the information we have.
- Mr. Boyd ordered 11 boxes of snow globe kits.
- The total number of kits used was 122.
- After the event, there were 10 kits left.
Let's denote the number of kits in each box as \( x \).
The total number of kits ordered can be expressed as: \[ 11x \]
According to the information given:
- Total kits used = Total kits ordered - Kits left over
- Rearranging this, we get: \[ \text{Total kits ordered} = \text{Total kits used} + \text{Kits left} \] Substituting the values, we have: \[ 11x = 122 + 10 \] This simplifies to: \[ 11x = 132 \]
Now, to find the value of \( x \), we divide both sides by 11: \[ x = \frac{132}{11} = 12 \]
Thus, the number of snow globe kits in each box is \[ \boxed{12} \]