Time and Work Questions

Directions: Read the information carefully and answer the questions. A, B, C and D together can do a work 'X' in 14 days. The ratio of efficiency of A to that of C is $3 : 2$. C is $50\%$ less efficient than that of B and B is $33\frac{1}{3}\%$ more efficient than D. A and B together can complete work 'X' in 'x' days, while A and D can do the same work together in 'y' days. 'j' men can complete a work in $(x + 4)$ day, while '$(y - 8)$' men can complete the same work in 'k' days. If '$(y + 2)$' men can complete the same work in $(0.5k + 3.5)$ days, then find in how many days $(k - j)$ men can complete the same work.