Schweser book 2 page 160 in the answer of the example: how did get get an expected return of 11.11%?

the question gives the following data: risk free rate: 2.5% spending rate: 8.5% inflation: 2% cost of managing the fund: 0.4% the answer is 11.11%. i have no idea how to get this.

1.085*1.02*1.004 - 1 = 11.11% spending rate times inflation times cost to manage fund. in this case the risk free is unnecessary information.

awesoome thanks a ton