A can do a work in 9 days and B can do the same work in 18 days. If they work together, in how many days will they complete the work?
Choose the correct choice from the following choices
A) 6 days	B) 7 days	C) 5 days	D) 3 days	E) 2 days

Rationale: one day ' s work of a and b = 1 / 9 + 1 / 8 = ( 2 + 1 ) / 18 = 1 / 6 so , the time taken to complete the work is 6 days . answer : a
Answer: A