Is my answer correct?

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

You have a 32-foot fence around a square garden. there are 4 equal sections. you paint 13 of one section of the fence. what fraction of the fence did you paint? you have a 32-foot fence around a square garden. there are 4 equal sections. you paint 13 of one section of the fence. what fraction of the fence did you paint?

Arecipe uses 2 cups of sugar to make 32 brownies. how many cups of sugar are needed to make 72 brownies?