75 is the total area of the floor, so divide that by how much square feet one tile covers. 75/2.25=33.3 You want to round up to the nearest whole number because you need that extra little 1/3 of tile to cover the whole floor. Make sure you NEVER round down. So now you would need 34 tiles after rounding up.
Next, multiply how many tiles you need by the cost of one tile. 34x1.79=$60.86