A, B and C can do a work in 9, 30 and 45 days respectively. If they work together, in how many days will they complete the work?  Pick one:
A) 5	B) 6	C) 7	D) 8	E) 11
One days's work of A, B and C = 1/9 + 1/30 + 1/45   = (10 + 3 + 2)/90 = 1/6   A, B and C together can do the work in 6 days.   Answer:6
<result>B</result>
A, B and C can do a work in 9, 30 and 45 days respectively. If they work together, in how many days will they complete the work?