24 men and 12 women can do a piece of work in 30 days. In how many days can 12 men and 24 women do the same piece of work?

The correct answer is Data is inadequate to draw any conclusion.

Let's analyze the problem step-by-step to understand why the given data is insufficient to find a unique numerical answer.

Let the daily work rate of 1 man be $m$ and the daily work rate of 1 woman be $w$.

According to the first statement, 24 men and 12 women can complete the work in 30 days.
Therefore, the total work $W$ can be represented as:
$W=30\times (24m+12w)$

We are asked to find the number of days, say $D$, in which 12 men and 24 women can do the same work $W$.
This gives us the equation:
$W=D\times (12m+24w)$

Equating the two expressions for the total work $W$, we get:
$30\times (24m+12w)=D\times (12m+24w)$

Solving for $D$:
$D=\frac{30\times (24m+12w)}{12m+24w}$
$D=\frac{30\times 12(2m+w)}{12(m+2w)}$
$D=\frac{30(2m+w)}{m+2w}$

From this equation, we can see that the number of days $D$ depends directly on the ratio of the efficiency of a man to that of a woman (i.e., the ratio $m/w$).

Since no relationship between the working efficiency of a man and a woman is provided in the question, we cannot simplify or calculate the value of $D$.
Therefore, the data provided is inadequate to draw any conclusion.