it takes 63 minutes for four people to paint nine walls how many minutes does it take seven people to paint four walls?

16 minutes

Step-by-step explanation:

If it takes 63 minutes to paint 9 walls then it means for every wall, it takes 63/9=7 minutes

Since it is 4 people working for 7 mins, the individual rate is 4/7 minutes per person

When we have 7 people, then the number minutes they take will be 7*4/7=4 minutes per wall

4 min per wall for 4 walls then total time will be 4*4=16 minutes