A rectangular swimming pool is 20 feet by 22 feet. A deck that has uniform width surrounds the pool. The total area of the pool and deck is 728 square feet. What is the width of the deck?  Choose the correct option: A) 2 B) 4 C) 3 D) 5 E) 6

Rationale: let the width = w total area of the pool and deck = ( 2 w + 20 ) ( 2 w + 22 ) we can test the answer choices along with unit digit method a ) 2 feet . . . . . . . . . . . 24 * 26 has unit digit 8 . . . . . . . . . . eliminate b ) 2.5 feet . . . . . . . . . 25 * 33 has unit digit 5 . . . . . . . . . . eliminate c ) 3 feet . . . . . . . . . . . . 26 * 28 has unit digit 4 . . . . . . . . . . . hold d ) 4 feet . . . . . . . . . . . . 28 * 30 has unit digit 0 . . . . . . . . . . . eliminate e ) 5 feet . . . . . . . . . . . . 30 * 32 has unit digit 0 . . . . . . . . . . . eliminate answer : c w = 3
Answer: C