Remaining paper
7 - 2 1/2 = 4 1/2
Equivalent Fraction:
4 1/2 = 9/2 = 18/4
if each piece is 1/4 of the sheets,
18/4 ÷ 1/4 = 18/4 x 4/1 = 18
I am slightly not too sure what the remaining papers is cut into 6 equal rectangle will imply in this question. But looking at the answer, 18, then it is possible that he cuts 3 triangles out from each rectangle (which he will still get 18) which makes the answer possible.
