In a community garden, Abe wants to plant 54 daisies and 27 daffodils. He wants to plant them in rows with an equal number of daisies and daffodils in each row. What is the greatest number of rows of flowers that Abe can plant?

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )