Hello, how would I go about answering this question?

Watson Corporation reports the following information that applies to 2020: Contribution margin ratio 30% Margin of safety $200,000 Operating leverage 4 Tax rate 25% Assuming unit sales price, unit variable costs, and total fixed costs would be the same in 2021 as they were in 2020, what would 2021 total dollar sales have to be in order to double 2020 net income