Jan buys 1000 feet of cable.  She splits it up into 25-foot sections.  She gives 1/4 of that to a friend.  She then puts half of the rest in storage. How much does she keep on hand?
She gets 1000/25=<<1000/25=40>>40 sections
She gives away 40/4=<<40/4=10>>10 sections
So she keeps 40-10=<<40-10=30>>30 sections
She keeps 30/2=<<30/2=15>>15 sections on hand
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