Question

Martha's bathroom is shaped like a rectangle with dimensions of 5ft by 7ft. The floor of the room is made of decorative square tiles with a side length of 1/4 ft. What is the number of decorative tiles Martha will need to purchase?

Answer 1

We know that

[area of Martha's bathroom]=5*7-----> 35 ft²

[area of one tiles]=(1/4)²-----> 1/16 ft²

if 1 tile has area of--------------> 1/16 ft²
 x tiles---------------------------> 35 ft²
x=35/(1/16)-----> x=35*16-----> x=560 tiles

the answer is
560 tiles