Question

Question 59. 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:

• A. (a) 15 days
• B. (b) 20 days
• C. (c) 25 days
• D. (d) 30 days

Answer 1

The correct option is C (c) 25 days

Answer 59.(c)
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.