I need help with a formula on how to figure up something on my basic business plan. This business plan will not be distributed to banks, but more for the family members helping in the work and financing of the business. I need a calculation that shows how effective one person is using a Quick 36 superduty at 5mph ground speed vs 2 people using a Craftsman and Troy built 21' self-propelled mower. I am not sure of the ground speed of a non-commercial 21' mower. If I am confusing anyone please let me know. I am trying to show justification on purchasing a quick36 vs buying 2 new 21' mowers. Especially when there is a chance I maybe working by myself now. My business is growing rapidly. In the last week I have went from 12 to about 17 yards. My goal for 30-40 yards next year should not be to hard to achieve.