"John John a trading company (JJTC) in N ew York managing a $2 million portfolio which has a beta of 2.1 and a required rate of return of 10%. The current risk free rate is 3.25 %. Assume that JJTC receive another $200K. If the company invest this money in a stock with beta 0.90, what will be the required rate of return on your $5.5 million portfolio" please step by step working

I submitted this question already and asked for clarity on it, (how did you get 13.575/2.1) still haven't received feedback. would really appreciate some help. thanks .