What is the BEST deal on oil?

• 1 pint of oil for $1.65
• 2 pints of oil for $3.40
• 5 pints of oil for $8.00
• 10 pints of oil for $17.50
• 20 pints of oil for $33.00

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?