is it possible to post a non-excel version of answer please?

Your uncle has $250,000 cash to start his retirement today. He is considering investing the entire sum in a 20-year retirement plan that promises to pay him $X at the start of every year for the first 10 years, and $2X at the start of the remaining 10 years (i.e. all annual payments will be made at the beginning of each year, with the first payment starting today). If the plan yields an effective annual return of 12%, what is the value of X