Please show step by step solutions.
1. A copier that originally cost $300 was sold on the installment plan as $28 per month for 12 months. Find the installment price if no down payment was made. Find the finance charge.
2. Find the yearly rate of interest on a loan if the monthly rate is 2%.
3. Office equipment was purchased on the installment plan with 12 monthly payments of $11.20 each. If the cash price was $120 and there was no down payment, find the annual percentage rate.