A company contracts to paint 3 houses. Mr.Brown can paint a house in 6 days while Mr.Black would take 8 days and Mr.Blue 12 days. After 8 days Mr.Brown goes on vacation and Mr. Black begins to work for a period of 6 days. How many days will it take Mr.Blue to complete the contract?

A. 7 B. 8 C. 11 D. 12

• 8/6+6/8+x/12=3
  32+18+2x=72
  2x=22
  x=11
• 11 years agoHelpfull: Yes(14) No(2)
• option c is correct..
  brown work for 8 days means he completed house 1st +(2/6) part of the house 2nd...in 8 days...
  remaining part of house 2nd = 1-(1/3)= 2/3.
  now black completes a house in 8 days but he works for 6 days ..so part of house completed by black = 6/8 =3/4..
  now part of house 3rd completed by black = (3/4)-(2/3) = 1/12..
  so means remaining part of house 3rd to be painted by blue = 11/12
  which he will complete in 11 days....
• 12 years agoHelpfull: Yes(12) No(2)
• let x is amount of work to be done to paint one house.
  So Brown's one day work is x/6, black's can do x/8 work in
  one day and blue is x/12.
  
  Total houses is 3, so tatal work to be done is 3x.
  
  3x= 8*(x/6) + 6*(x/8) + y*(x/12)
  
  finally y = 11.
  
  blue will complete the remaining work in 11 days.
  
• 11 years agoHelpfull: Yes(7) No(1)