Problem / game
First name
Ayaansh Dhamija
School
Vichar Vatika - Ganit Kreeda
Country
Age
9
How I figured it out:
The rules say the number in each box has to be the average of the 4 circles around it. But the two boxes are touching each other! That means the left box counts as a number for the right box, and the right box counts as a number for the left box.
Let's call the left box X and the right box Y.
My Equations:
For the left box X, the numbers around it are 7, 20, 2, and Y.
- $X = (7 + 20 + 2 + Y) \div 4$
- $4 \times X = 29 + Y$
For the right box Y, the numbers around it are 15, 3, 1, and X.
- $Y = (15 + 3 + 1 + X) \div 4$
- $4 \times Y = 19 + X$
- $X = (4 \times Y) - 19$
Finding the numbers:
Now I change the X in my first equation to be $(4 \times Y) - 19$.
- $4 \times ((4 \times Y) - 19) = 29 + Y$
- $(16 \times Y) - 76 = 29 + Y$
Move the Y to one side and numbers to the other side:
- $15 \times Y = 29 + 76$
- $15 \times Y = 105$
- $Y = 105 \div 15$
- $Y = 7$
Now that I know Y is 7, I can easily find X:
- $X = (4 \times 7) - 19$
- $X = 28 - 19$
- $X = 9$
My Final Answers:
- Left Box = 9
- Right Box = 7