Isomer Industrial Training Corporation is considering the purchase of new presentation equipment at a cost of $150,000. The equipment has an estimated useful life of 10 years with an expected salvage value of zero. The equipment is expected to generate net cash inflows of $35,000 per year in each of the 10 years. Isomer's discount rate is 16%. Isomer uses the straight-line method of depreciation for its assets.What is the payback period of the presentation equipment?