Help me with the whole 4 questions with the right please

A year ago, Crunchy Cola Corporation bought a stamping machine to make the cans for its cola. The cost of the machine was $60,000. The machine has a useful life of 5 years and a salvage value of zero at the end of those five years. Annual depreciation on the machine is $12,00. One year of depreciation has been recorded. The variable manufacturing cost is the annual depredation of $12,000 on the stamping machine. Crunchy needs 200,000 cans annually. Dagmar Stamping Company recently gave Crunchy an offer to supply all of its can needs for the next four years at $0.07 per can. If Crunchy buys from Dagmar, the stamping machine would not be needed and would be sold for $35,000. Crunchy buys from Dagmar, what will be the total dollar increase or decrease in income for the next four years? a. $16,000 b. $19,000 c. $29,000 d. $32,000 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 zero. The equipment is expected to generate net cash inflows of $35,000 per year 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? a. 2.3 b. 3.0 c. 4.3 d. 5.8 Under a standard cost system, the materials price variances are usually the responsibility of the: a. production manager. b. sales manager. c. purchasing manager. d. engineering manager. The payback method is criticized on the grounds that it a. ignores obsolescence factors. b. ignores the cost of an investment. c. is complicated to use. d. ignores the time value of money