need solution on excel sheet

(Portfolio selection) A provincial teachers' pension fund has $250000 available to invest in a 12 -month commitment. The money can be placed in provincial bonds (with a return of 8% and a risk score of 2 ) or in an equity account (with a return of 9% and a risk score of 3 ). Pension fund regulations require diversification to the extent that between 50% and 70% of the total investment must be placed in provincial bonds. Also, due to past defaults in other provincial funds, it is decided that the average risk score of the total investment should be no more than 2.42 . How much should the teachers' pension fund invest in each security to maximize its return on investment