Please post step by step solutions for the excel solver

A lumber store stocks dowels in one standard length of 150 cm. Each dowel costs $20. A customer wants the store to cut him at minimal cost twenty dowels of length 67 cm, eighty dowels of length 51 cm, sixty dowels of length 28 cm, and forty dowels of length 15 cm. You might wish to use Excel to help create a list of patterns when beginning part (a). (a) Formulate an algebraic model for the problem. Submit this in Word or pdf. (6) Use the Excel Solver to solve this model. Submit the computer file. (c) State the solution in words. Submit this in Word or pdf