Answer: 24 hours
Step-by-step explanation: If it took 12 men 12 hours to construct a wall, then it would take 6 men longer.
If 12 divided by 12 is one, that means each man took one hour to work.
If 12 divided by 6 is two, that means each man takes two hours to work.
6 times 2 is 12, and 12 times 2 is 24. It takes 24 hours to complete the wall.
You multiply 6 times 2 because each man works 2 hours, so 12 equals the number of hours all the men worked in total.
You do 12 times 2 because if each men works 2 hours and there are 6 men, they work a total of 12 hours. You do 12 times 2 because it is going to take the men double the amount of time to complete the wall because 6 is half of 12.