A box contains a collection of triangular and square tiles. There are 2525 tiles in the box, containing 8484 edges total. How many square tiles are there in the box?

Let us consider the number of edges = x

we know that a triangle will have 3 edges and a square will have 4 edges. Using this details we can form an equation.

3x + 4x = 8484

7x = 8484

x = 8484/7

= 1212

Then

Number of square tiles = 1212/4

= 303

So there are 303 square tiles in the box. I hope the procedure is clear enough for your understanding. You can always use this method for solving similar problems.