calculate the payback period

Company DEF has enjoyed several consecutive profitable years and has accumulated $80,000,000 in cash and marketable securities. The company is considering multiple potential uses for the excess cash. Option 1: Build a new manufacturing facility at an initial cost of $20,000,000. The facility is expected to generate an additional $7,000,000 in annual sales. Assume no new fixed costs and variable costs equal to 55% of sales. For depreciation calculations, assume a 10-year life and straight-line depreciation