Question

Nina glues pictures on a rectangular piece of cardboard. The piece of cardboard is 20 inches long and 9 inches wide. Each rectangular picture is 7 inches long and 4 inches wide. She glues 3 pictures on the cardboard. The pictures do not overlap. What is the area of the cardboard that is not covered by pictures?

Answer 1

we know that

[area of the rectangular piece of cardboard]=20*9-----> 180 in²

[area rectangular pictures]=3*[7*4]-----> 84 in²

[area of the cardboard that is not covered by pictures]=180-84----> 96 in²

the answer is
The area of the cardboard that is not covered by pictures is 96 in²