A and B can do a work in 5 days, B and C in 15 days and C and A in 25 days. In how many days will the work be completed, if all three of them work together?  Choose one:
A) 26/18 B) 42/15 C) 48/63 D) 12/36 E) 150/23
One day work of A and B = 1/5   One day work of B and C = 1/15   One day work of C and A = 1/25   2(A + B + C) = 1/5+ 1/15 + 1/25   2(A + B + C) = 23/75   (A + B + C) = 23/150   Number of days required = 150/23 days.   Answer: 150/23
<result>E</result>
A and B can do a work in 5 days, B and C in 15 days and C and A in 25 days. In how many days will the work be completed, if all three of them work together?