Let's assume that the job requires x workers to complete it in 12 hours.
We can use the following formula:
workers × time = constant
Therefore, for 3 workers to complete the job in 28 hours, we have:
3 × 28 = 84
For x workers to complete the same job in 12 hours, we have:
x × 12 = 84
Solving for x, we get:
x = 7
Therefore, we need 7 workers to complete the job in 12 hours, which is 4 more workers than the initial 3.