Question 460075
Three men can do the job at painting a house in 37 days.
Find the number of man-days to do the job
3 * 37 = 111 man-days to paint the house
:
If another 6 men joined them 7 days after they started painting.
How many more days will they finish painting?
:
Let d = no. of man days to complete the job, 
After 7 days there will be 9 men working.
:
3(7) + 9d = 111
21 + 9d = 111
9d = 111 - 21
9d = 90
d = 10 days to finish the house