A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work in 23 days. The number of days after which A left the work was

• A does the job in 45 days = 1/45
  B does the job in 40 days = 1/40
  A & B together completes the job = ?
  After A leaves, B completes the remaining job in 23 days.
  i.e B's part of job in 23days = 23/40
  Remaining part 17/40 is done by A & B together in x no.of days.
  i.e (x/45) + (x/40) = 17/40
  ==> x = 9 days
  Soln:
  A leaves after 9 days.
• 12 years agoHelpfull: Yes(15) No(2)
• (A+B)’s 1 day’s work = 1/45 + 1/40 = 17/360
  
  Now work done by B in 23 days=1 * 23/40= 23/40.
  
  Remaining work = 1-23/40= 17/40
  
  Now, 17/360 work was done by (A+B) in 1 day.
  
  therefore, 17/40 work was done by (A+B) in 360/17 * 17/40 = 9 days.
• 9 years agoHelpfull: Yes(0) No(2)
• ans is 9 days for A
• 5 years agoHelpfull: Yes(0) No(0)
• (A+B)'s 1 day's work = 1/45+1/40=17/360
  
  Work done by B in 23 days = 1×23/40=23/40
  
  Remaining work = 1−2340=1740
  
  Now, 17/360 work was done by (A+B) in 1 day.
  
  17/40 work was done by (A+B) in 1×360/17×17/40=9 days
  
  Therefore, A left after 9 days.
• 5 years agoHelpfull: Yes(0) No(0)
• x/45 + (x+23)/40 = 1
  => (8x + 9x + 207)/360 = 1
  => 17x = 153
  => x = 9
• 5 years agoHelpfull: Yes(0) No(0)