Help will give 40 points

Issof claims that the scale factor is 1/2. which statement about his claim is correct

For each proportion find the unknown number x 1/5/8=×/15

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?