You are being very vague on the terms of the cash game portion of the stake. Set some defined hours, and play prior to the tournaments. That way you can't adjust your allocation of time depending on how you do in the tournaments.

As far as the 23.6%, I looked at the percentage you would get if you only invested in the tournaments with 2k (2000/5500 = .3636* .65 = 23.6%), compared to if you invested in the entire package (2000/10000= .20 * .65 = 13%)