It would take 1 hour for each member if there are 45 members to paint a wall, so it's 45 hours in total.

Let \(x\) represent how many hours 12 members need to paint the same wall.

\(12x=45 \times 1\)

\(x=\frac{45}{12}=\frac{15}{4}\)hrs

In minutes, it would be \(3 \times \frac{15}{4}=225 \) minutes.