Explanation:

Correct Option :1 

A man completes the work in 6 days, so his work rate is 1/6 of the work per day.

A woman finishes the same work in 12 days, so her work rate is 1/12 of the work per day.

Working together, their combined work rate is 1/6 + 1/12 = 1/4 of the work per day.

Together, they can complete the work in 4 days because 1 divided by their combined rate (1/4) equals 4.

Hence option 1 =4 days is the correct answer

- Option 1: 4

- This is correct based on the calculations above.

- Option 2: 3

- This option is incorrect as the combined rate would need to be higher.

- Option 3: 5

- This option is incorrect, as it means their rate would be slower than calculated.

- Option 4: 3

- Same incorrect reasoning as Option 2.