If a rectangular billboard has an area of 91 square feet and a perimeter of 40 feet, what is the length of each of the shorter sides?
Choose the correct answer:
A) 4	B) 7	C) 8	D) 13	E) 26

Rationale: "this question can be solved algebraically or by testing the answers . we ' re told that a rectangle has an area of 91 and a perimeter of 40 . we ' re asked for the length of one of the shorter sides of the rectangle . since the answers are all integers , and the area is 91 , the shorter side will almost certainly be less than 10 ( since 10 x 10 = 100 , but we ' re not dealing with a square ) . let ' s test answer b : 7 if . . . the shorter side = 7 . . . the area = 91 . . . . 91 / 7 = 13 = the longer side perimeter = 7 + 7 + 13 + 13 = 40 b"
Answer: B