Find a System of Inequalities Describing the Following Problem

Short Answer

Find a system of inequalities describing the following problem. A store sells two brands of VCRs. Customer demand indicates that it is necessary to stock at least twice as many VCRs of brand A as of brand B. At least 20 of brand A and 15 of brand B must be on hand. There is room for not more than 110 VCRs in the store.