Answer : Option A

Explanation :

I. (10 x 6) men can complete the work in 1 day.

  1 man's 1 day's work = \(\frac { 1 } { 60}\)

II. \( [10*\frac { 24 } { 7 } ]\)men+\( [10*\frac { 24 } { 7 } ]\) women can complete the work in 1 day.

 \([\frac {240 } { 7} ]\) men's 1 day work +\([\frac {240 } { 7} ]\) women's 1 day work = 1

[\(\frac {240 } { 7}\) x \(\frac {1 } { 60} \)] +\([\frac {240 } { 7} ]\) women's 1 day's work = 1

 \([\frac {240 } { 7} ]\)women's 1 day's work =[1-\( \frac { 4 } { 7 } \)] =\(\frac { 3 } { 7 } \)

10 women's 1 day's work =[  \(\frac { 3 } { 7 } \)x\( \frac {7 } { 240 }\)x 10] =\(\frac { 1} { 8 } \)

So, 10 women can finish the work in 8 days.

III. (10 men's work for 3 days) + (10 women's work for 4 days) = 1

       (10 x 3) men's 1 day's work + (10 x 4) women's 1 day's work = 1

       30 men's 1 day's work + 40 women's 1 day's work = 1

      Thus, I and III will give us the answer.

      And, II and III will give us the answer.

   Correct answer is (A)