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.