3. Stan is deciding between patio tiles that are 39 cm by 39 cm and tiles that are 18 cm

by 27 cm. His patio is 3 m by 2.5 m. Considering area only, how many of each type

of tile would he need?

Stan needs about 50 of the 39 cm x 39 cm tiles

or about 155 of the 18 cm x 27 cm tiles

Step-by-step explanation:

Since we are asked to consider only matters of area, we need to calculate first, the area of the patio:

Patio area = 3 m x 2.5 m = 7.5 m^2

Now we consider what surface (in square meters - m^2) each type of tiles cover:

a) for the 39 cm x 39 cm tiles: 0.39 m x 0.39 m = 0.1521 m^2

b) for the 18 cm x 27 cm tiles: 0.18 m x 0.27 m = 0.0486 m^2

Therefore, to cover the area of the patio, the number of tiles type "a" needed is given by the quotient:

7.5 m^2 / 0.1521 m^2 = 49.3096 (about 50 tiles)

while for type "b" tiles the quotient gives:

7.5 m^2 / 0.0486 m^2 = 154.32 (about 155 tiles)