The brand of cartridge which is the best buy us the brand with the lowest unit price which is brand A.
Brand A
Cost = $20
pages = 200
Unit price = $20/200
= $0.1 per page
Brand B:
Cost = $25
Pages = 125
Unit price = $25/125
= $0.2 per page
Brand C:
Cost = $30
Pages = 150
Unit price = $30 / 150
= $0.2 per page
Brand D:
Cost = $35
Pages = 250
Unit price = $35 / 250
= $0.14 per page
Therefore, the brand of cartridge which is the best buy us the brand with the lowest unit price which is brand A.
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