SOLUTION: you and a group of friends offer to help paint a house. you need to paint 4 rooms in 8 hours. if each person can paint one room in 10 hours, how many people will it take to paint a

Algebra ->  Rate-of-work-word-problems -> SOLUTION: you and a group of friends offer to help paint a house. you need to paint 4 rooms in 8 hours. if each person can paint one room in 10 hours, how many people will it take to paint a      Log On


   

Question 770901: you and a group of friends offer to help paint a house. you need to paint 4 rooms in 8 hours. if each person can paint one room in 10 hours, how many people will it take to paint all rooms on time.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The job can be identified as 1 room, and you want a rate of 4/8 room per hour. This is 1/2 room per hour rate. The rate of 1 person or 1 friend is 1/10 room per hour.

The objective is find how many friends including yourself will achieve a rate of at least 1/2 room per hour. We assume the rates of all friends in the group of painters are additive.

highlight%28n%2A%281%2F10%29=1%2F2%29
n=10%2F2
n=5
'
The group must have 5 people to do the painting for the expected rate.