58.A can do a piece of work in 4 hours; B and C together can do it in 3 hours, while A and C together can do it in 2 hours. How long will B alone take to do it?
A. 8 hours
B. 10 hours
C. 12 hours
D. 24 hours
Answer:
Option : C
(B + C)'s 1 hour's work =
|
1
|
3
|
(A + C)'s 1 hour's work =
|
1
|
2
|
(A + B + C)'s 1 hour's work =
|
|
1
|
+
|
1
|
|
=
|
1
|
4
|
3
|
12
|
B's 1 hour's work =
|
|
7
|
-
|
1
|
|
=
|
1
|
12
|
2
|
12
|
∴ B alone will take 12 hours to do the work.
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