A and B caan finish typing a manuscript in 8/3 days; B and C together, in 40/9 days; A and C together in 20/7 days. How long will each, working alone type the manuscript?

Answer 1

work done = (actual time worked) / (req'd time to finish a task)

'completed' work = 1

so let
A = time req'd for A
B = time req'd for B
C = time req'd for C

there will be 3 equations:

(8/3A) + (8/3B) = 1

(40/9B) + (40/9C) = 1

(20/7A) + (20/7C) = 1

use elimination method to solve the problem.

Answer 2

So if i eliminate C first would the resulting two equations be:

(8/3A) + (8/3B) = 1
(1/A) + (1/B) = (-8/20)

???????