Answer:
42 minutes
Step-by-step explanation:
I think this problem should read:
"If it takes 54 minutes for 4 people to paint 6 walls. How many minutes does it take 6 people to paint 7 walls?"
The fewer people working, the more time it takes, so to go from more people to fewer people, multiply the time to give a larger number. To go from fewer people to more people, divide the time to give a smaller number.
The more walls, the more time it takes, so to go from fewer walls to more walls, multiply the time to give a larger number. To go from more walls to fewer walls, divide the time to give a smaller number.
"it takes 54 minutes for 4 people to paint 6 walls"
then
it takes 9 minutes for 4 people to paint 1 wall (1/6 of the walls in 1/6 of the time)
and
it takes 36 minutes for 1 person to paint 1 wall (1/4 of the people take 4 times longer)
then
it takes 252 minutes for 1 people to paint 7 walls (7 walls take 7 times the time of 1 wall)
and
it takes 42 minutes for 6 people to paint 7 walls (6 people work 6 times faster than 1)
