Answer:
It would take 34.5 minuets for 9 people to paint 9 walls
Step-by-step explanation:
Divide 23 by 2 and you sound get 11.5
and 11.5 to 23 to get 34.5
The reason you must do it like this is because if they all do it at the same rate you need to know how long it would to for 3 people to do it so that you have a minimum point, then add the mid and min points to get the max point, 9 people.
