Answer:
C: 48 straws
Explanation:
First, find the perimeter of one picture frame: (2 x length) + (2 x width). Convert 20 centimeters to millimeters so that you are working in the same units; there are 10 millimeters in 1 centimeter, so 20 centimeters = 200 millimeters.
(2 x 200) + (2 x 120) = 400 + 240 = 640
Each picture frame has a perimeter of 640 millimeters.
Next, figure out how many straws are needed for one picture frame:
640/80 = 8
Jana uses 8 straws for each picture frame. Since she is decorating 6 picture frames, solve 6 x 8 = 48.
Jana needs 48 straws to complete her project.