A work as fast as B. If B can complete a work in 12days independently,the number of days in which A and B can together finish the work in? Choose the most appropriate option:	A) 2 days	B) 3 days	C) 4 days	D) 5 days	E) 6 days

Rationale: ratio of rates of working of a and b = 2 : 1 ratio of times taken = 1 : 2 a ' s 1 day work = 1 / 6 b ' s 1 day work = 1 / 12 a + b 1 day work = 1 / 6 + 1 / 12 = 3 / 12 = 1 / 4 a and b can finish the work in 4 days answer is c
Answer: C