Sally wants to put lights all around her windows. She has 15 windows all the same. Each one is 3 feet long and 2 feet wide. How many strands of lights will she need to buy if each strand covers 10 feet? How much will it cost her if each strand of lights costs $6.99? Don't forget that there is a 7% sales tax.
P = 2L + 2W
P = 10 feet for each window.
15 * 6.99 * 1.07 = ?