Question

An electronics store sells DVD players and cordless telephone. The store makes a $75 profit on the sale of each DVD player (d) and a $30 profit on the sale of each cordless telephone (c). The store wants to make a profit of a least $255.00 from its sales of DVD players and cordless phones. Write an inequality to model this situation.
Find an example to show how this situation could happen and one example showing how it could NOT happen. Make sure to justify your answer.

Answer 1

Inequality

75d + 30c ≥ 255

Examples

(1) If someone bought five DVD players and ten cordless telephones, the equation ((75)(5)+(30)(10)≥255) would be true.

(2) If the electronic store had a parcticularly bad day and they sold two DVD players and one cordless telephone, the equation ((75)(2)+(30)(1)≥255) would be false.