Even though the number of tiles changes the floor area did not change. Thus \(A_f = 480A_1 = 270 A_2\)

Where \(A_1\) is the area of a tile from the original tile and \(A_2\) is the area of one tile afted the addition of 3 inches.

Thus if \(x\) is the side of one tile, then the second is \(x+3\).

\(480A_1 = 270A_2\)

\(48(x^2) = 27(x+3)^2\)

\(\frac{4}{3}x = x+3\)

\(\frac{1}{3} x= 3\)

\(x = 9 \) inches

Thus the lenght of a side of the tile is 9 inches.