Answer:
4 days to complete the work.
Step-by-step explanation:
6 MEN OR 8 WOMEN
means that each man completes the 1/(6*12) of the work per day
OR each women completes 1/(8*12) of the work per day
9 MEN AND 12 WOMEN completes …..
9 * 1/(6*12) + 12* 1/(8*12) of the work per day.
Note that we add these 2 fractions because of the word ‘AND’ .
that gives us a simple fraction of 1/4 of the work per day.
Thus reversing it, gives you time taken = 4 days to complete the work.