A can do a work in 8 days. B can do the same work in 16 days. If both A & B are working together in how many days they will finish the work?  Answers:	A) 3 days	B) 16 / 3 days	C) 3 / 4 days	D) 9 / 12 days	E) 5 / 7 days

Rationale: "a rate = 1 / 8 b rate = 1 / 16 ( a + b ) rate = ( 1 / 8 ) + ( 1 / 16 ) = 3 / 16 a & b finish the work in 16 / 3 days correct option is b"
Answer: B