Question

It takes 36 minutes for 7 people to paint 4 walls.
How many minutes does it take 9 people to paint 7 walls?

Answer 1

Answer:

49 minutes

Step-by-step explanation:

It would take 49 minutes for 9 people to paint 7 walls.

4 walls need 262 people/minutes (7)(36)

9 people could do that in 49 minutes (441/9)

Answer 2

Answer:

49 minutes

Step-by-step explanation:

first we need to find the rate at which a person paints the walls :

it takes 36 minutes  to paint 4 walls   by 7 people :

so for 7 people the rate at which they paint the walls is : $\frac{4}{36}$ walls/minute

if we simplify we get  $\frac{1}{9}$

now that was for 7 people , for 1 person the rate is : $\frac{1}{9} \frac{1}{7}$ which is $\frac{1}{63} walls / minute$

now we have the rate for one person

so for 9 people they will paint $\frac{9}{63} =\frac{1}{7}$ walls/minute

so it takes them 7 minute to paint 1 wall

which means it takes them 7 x7 = 49 minutes to paint 7 walls