Please help!
Hopefully the attached image makes sense.

In the image, point a marks the center of the circle. which two lengths must form a ratio of 1 : 2? (options are in the images since thought they were harmful phrases)

Jane’s favorite fruit punch consists of pear, pineapple, and plum juices in the ratio 5: 2: 3. how many cups of pear juice should she use to make 20 cups of punch?

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great