I need help with the calculations on how to get to the above answers

Project C15 Alpha -$250,000 $849,900 Beta -$650,000 $1,953,500 Assume that the firm has a WACC of 7.5% and that projects Alpha and Beta are mutually exclusive. 3. Using the information in the table above, find Project Alpha's IRR. a. 3.5% b. 7% C, 8.5% d. 10.5% 4. Again using the information in the table above, determine the incremental IRR. What conclusion should we draw from the incremental IRR alone? a. 7%; we should undertake Beta 6.7%; we should not undertake Beta c. 7%; we should undertake Alpha d. 7.6%; we should undertake both projects