SSC CPO SI and ASI 2011 Paper

(3) Work done by (A + B) is $\frac{11}{19}$and
work done by (B + C) is $\frac{14}{19}$
As work done by (A + B + C) is 1,
Work done by A will be $1-\frac{14}{19}=\frac{5}{19}$
Work done by C will be..
And Work done by B will be $1-\frac{13}{19}=\frac{6}{19}$
Therefore, the ratio amongst work done by A, B and C is 5 : 6 : 8.