plz explain how to do this prob? james bought 80 postage stamps for which he payed 3.50 some were 3 cents some were 5 how many of each did he buy? Related posts: the post office only has stamps of the denomination 5cents and 7cents.what amount of postage will you buy? ? Question about first class postage stamp Is it legal for a convenience store to charge me more for postage stamps than the stamps are worth?