George and mark work for a comapny. George can finish a certain job in 30 days. Mark can finish the same job in 45 days. A project was taken by the company and George was made superior to Mark. This move from the company was not liked by mark. So Mark did not work for 15 days. Find the total number of days the entire work was completed if Mark works at his normal speed after 15 days from the date of commencement?
Option
a) 15
b) 20
c) 35
d) 24

• If George and mark works together they complete it in 18 days.
  
  (i.e) - 1/G + 1/M = 1/18
  
  if George worked for 15 days he would complete 1/2 of work.
  Remaining 1/2 of work will be completed in 18x1/2 = 9 days.
  
  Then total days worked will be 15+9 = 24 days
• 10 years agoHelpfull: Yes(17) No(1)
• 1/G=1/30
  1/M=1/45
  Let the days where mark worked with george is x.(after the 15 days period where george worked alone)
  then work done by george is for (15+x) days and for mark is x days
  hence,
  (15+x)/30 + x/45 = 1
  x=9 days
  So the total number of days for the entire work completion is 15+9= 24days
  option d
  
• 10 years agoHelpfull: Yes(10) No(0)
• l.c.m of 30 &45 is 90
  so george efficiency is 3
  mark =2
  since for 1st 15 days george work so work complested =15*3=45
  reaming work=90-45=45
  tat ca be cmpleted by both so 45/(3+2)=9
  total days =15+9=24 ans
• 8 years agoHelpfull: Yes(3) No(0)
• it will be completed in 24 days
• 10 years agoHelpfull: Yes(1) No(4)
• (15+x)/30 + x/45 = 1
  x=9 days
  
  work completion is 15+9= 24days
• 10 years agoHelpfull: Yes(1) No(0)
• Ans is 24
• 7 years agoHelpfull: Yes(0) No(0)