A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in: Choose the correct choice from the following choices.
A) 15 days
B) 20 days
C) 25 days
D) 30 days
E) 35 days
Explanation:   (A + B)'s 1 day's work =1/10   C's 1 day's work =1/50   (A + B + C)'s 1 day's work =1/10+1/50=6/50=3/25.. (i)   A's 1 day's work = (B + C)'s 1 day's work .... (ii)   From (i) and (ii), we get: 2 x (A's 1 day's work) =3/25   A's 1 day's work =	3/50   B's 1 day's work=1/10-3/50=2/50=1/25   So, B alone could do the work in 25 days.   ANSWER IS 25 days
<result>C</result>
A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in: