Arnold and Danny are two twin brothers that are celebrating their birthday. The product of their ages today is smaller by 17 from the product of their ages a year from today. What is their age today?	Pick one.
A) 2 .	B) 4 .	C) 5 .	D) 7 .	E) 8 .

Rationale: "ad = ( a + 1 ) ( d + 1 ) - 17 0 = a + d - 16 a + d = 16 a = d ( as they are twin brothers ) a = d = 8 e is the answer"
Answer: E