Answer:
8 men
Explanation:
From the information, we can see that the number if days is inversely proportional to the number of men. When the number of days decreases, the number of men increases.
So,
30 = k / 12 (k is the constant)
k = 360
Now, number of days = 30 -12 = 18 days
So, we can see that the number of men increases because the number of days decreases.
Let a be the number of men required
18 = 360 / a (Since k is constant, its value will be unchanged)
a = 20
Now, the new number of men is 20, while the previous number is 12; so, number of more men = 20 - 12 = 8 men