4 men can develop a mobile app in 3 days. 3 women can develop the same app in 6 days, whereas 6 boys can develop it in 4 days. 3 men and 6 boys worked together for 1 day. If only women were to finish the remaining work in 1 day, how many women would be required?

Let’s first find the work done by each group in one day, which we can call their work rate. We’ll denote the total work to develop the app as 1 unit of work.

– 4 men can develop the app in 3 days, so their work rate is \( \frac{1}{3 \times 4} = \frac{1}{12} \) of the work per day per man.
– 3 women can develop the app in 6 days, so their work rate is \( \frac{1}{6 \times 3} = \frac{1}{18} \) of the work per day per woman.
– 6 boys can develop the app in 4 days, so their work rate is \( \frac{1}{4 \times 6} = \frac{1}{24} \) of the work per day per boy.

Now, 3 men and 6 boys worked together for 1 day. The work done by them in 1 day is:

\[ 3 \times \frac{1}{12} + 6 \times \frac{1}{24} = \frac{1}{4} + \frac{1}{4} = \frac{1}{2} \text{ of the work} \]

So, half of the work is remaining.

If only women are to finish the remaining half of the work in 1 day, the number of women required is:

\[ \text{Number of women} = \frac{\text{Remaining work}}{\text{Work rate of one woman}} = \frac{1/2}{1/18} = 9 \text{ women} \]

Therefore, 9 women would be required to finish the remaining work in 1 day.