1. Myrnas Mowing Ltd. cuts lawns. It has a riding lawnmower with a book value of $5,000, and a remaining useful life of 5 years. A new, more efficient lawnmower is available with a cost of $15,000. The useful life of the new machine is also expected to be 5 years. Myrna estimates that the new machine will allow her to cut more lawns, and therefore increase revenue from $20,000 per year to $22,000, and reduce variable costs from $12,000 per year to $10,500. Prepare an analysis showing whether Myrna should retain the old mower, or buy new.