Amosaic is made by having 1 cm square tiles glued onto a photograph. the photograph is a 6 cm by 8 cm rectangular photo. it is enlarged by a scale factor of 1.5. how many tiles are needed to cover the enlarged photo

A scale factor is the ratio of two similar geometric figures of their corresponding sides. The scale factor is calculated by locating the corresponding sides on each figure. Enlargement of a figure would have a scale factor that is greater than 1 which is evident for the problem above. To determine how many tiles would be needed to cover the enlarged photo, we need to know the new dimension of the photo. We do as follows:

Old photo = 6 cm x 8 cm
New photo = 6 cm x 1.5 x 8 cm x 1.5
                  = 9 cm x 12 cm

Number of tiles = Area of photo / Area of tiles
             Area of photo = 9 x 12 = 108 cm^2
             Area of tiles = 1 cm x 1 cm = 1 cm^2

Number of tiles = 108 cm^2 / 1 cm^2 = 108 tiles