Question: 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?
Solution:
She gets 1000/25=40 sections
She gives away 40/4=10 sections
So she keeps 40-10=30 sections
She keeps 30/2=15 sections on hand
Answer: 15