Question:
Mary decorated a rectangular piece of cardboard using stars and smiley faces. On the top part, there were 2 stars for every 9 cm of length of the cardboard. On the bottom part, there were 5 smiley faces for every 12 cm. The stars and smiley faces were placed at an equal distance apart as shown.
(a) A total of 552 stars and smiley faces were used to decorate the cardboard. How many smiley faces were there?
(b) Next, Mary wants to tie a ribbon under each smiley face as shown below. Each ribbon measures 6 cm long.
Given that ribbons were sold in rolls of 80 cm each, how many rolls of ribbons does Mary need to buy?