Let A's efficiency be $2x$ and B's efficiency be $x$.

• A can finish the work in 12 days, working 8 hours per day.
• Total work done by A in 12 days is:

$\text{Total work} = \text{Efficiency} \times \text{Total hours} = 2x \times (12 \times 8) = 192x \text{ units}$

Now, let’s calculate the time B would take to complete the same work:

$\text{Total work} = 192x$

• B’s efficiency is $x$.
• B works 12 hours a day. Let $d$ be the number of days B takes to finish the work.

$\text{Total work} = \text{Efficiency} \times \text{Total hours} = x \times (12 \times d) = 12xd$

Setting both expressions for total work equal:

$192x = 12xd$

$192 = 12d$

$d = 16$

So, B can finish the same work in 16 days.

Would you like more details or have any questions? Here are some related questions:

1. How do you determine the efficiency of a worker?
2. What happens if both A and B work together?
3. How can we calculate work done if the efficiency varies over time?
4. What if A works more hours per day?
5. How does changing the number of hours worked per day affect completion time?

Tip: To solve work and efficiency problems, always define the efficiency in terms of work units per hour or day to simplify calculations.