A small office supply store sells paper clips in packs of 100 and packs of 250. If the store has 84 packs of paper clips in stock totaling 12,300 paper clips, how many paper clips would a customer buy if he buys half of the packs of 250 that the store has in stock?

Let x and y be the number of packs with 100 and 250 paper clips, respectively. The system of linear equations that would best represent the given is

x + y = 84

100x + 250y = 12,300

The values of x and y from the equations are 58 and 26, respectively. If a person buys half of the packs of 250 paper clips,

n = (0.5) (250) (26) = 3250

Thus, a person bought 3250 paper clips.