One day, he bought 10 pairs of socks for $2.50 each and 3 pairs of shoes for dollars each. he spent a total of $135.97. write and solve an equation to find the cost of one pair of shoes. the following day cory returned to the store to purchase some more socks. he had $40 to spend. when he arrived at the store, the shoes were on sale 1/3 off. what is the greatest amount of pairs of socks cory can purchase if he purchases another pair of shoes in addition to the socks?