Each pattern has its own fabric requirements: A jelly roll or fabric from a bolt may be used.
Bargello Diamond Wall requires 1/4 yd (6") of 10 different fabrics. If a jelly roll is used, the student needs to assure that there are 2 identical strips of each of the 10 colors.
Twin Diamond requires 1/3 yd (12") of 20 different fabrics. If a jelly roll is chosen you will need 4 identical strips of each color. Two jelly rolls will probably be needed. The Hoffman Bali Poppies contain 20 strips each and would work great: https://tinyurl.com/vc9f452
Bargello Peaks requires 1/4 yd (6") of 20 different fabrics. A jelly roll would require 2 identical strips of 20 fabrics.