A job can be completed in 30 days by 12 men. If the job is required to be completed in 12 days earlier, how many more men are required
if they are working at the same rate?

8 men

Step-by-step 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