answer
8 = 160
5 = 100
4 = 80
2 = 40
Explanation:
20 x 8= 160
20 x 5 = 100
20 x 4 = 80
20 x 2 = 40
we don't know when the membership is charged, so I am going to guess that it is only charged once.
20 x 8= 160
20 x 5 = 100
20 x 4 = 80
20 x 2 = 40
20 x 1 = 20 + 80 = 100