A finishes a work in 8 hrs,B finishes a work in 10 hrs,C finishes a work in 12 hrs.A,B,C work together but A leaves after 2 hrs find the time t taken by B & C?

• A's 1 hour work =1/8
  B's 1 hour work=1/10
  c's 1 hour work=1/12
  (A+B+C)'s 2 hour work=2*(1/8+1/10+1/12)=37/60
  remaining work=1-37/60=23/60
  (B+c)'s 1 hour work=(1/10+1/12)=11/60
  therefore time taken by B and C=23/60*60/11=23/11hrs
• 10 years agoHelpfull: Yes(54) No(1)
• A+B+C=1/8+1/10/+1/12=37/120
  B+c=22/120
  after 2 hour A leaves.
  remaining work=1-(2*37/120)=46/120
  B+C can do 46/120 in (46/120)*(120/22)=23/11 hour
• 10 years agoHelpfull: Yes(4) No(0)
• sorry this is the rit ans
  if A ,B and C working together then in 1hr , work done by them ..
  (1/10)+(1/8)+(1/12) = 37/120
  in 2 hrs work done by them will be = 74/120
  remaining work= 1- 74/120 = 46/120 = 23/60
  work done by B&C in 1 hr = (1/10)+(1/12)= 11/60
  to do 23/60 B&C require = 23/11 hrs
  
• 10 years agoHelpfull: Yes(2) No(0)
• if A ,B and C working together then in 1hr , work done by them ..
  (1/10)+(1/8)+(1/12) = 37/120
  in 2 hrs work done by them will be = 54/120=27/60
  remaining work= 1-(27/60)=33/60
  
  if B and C are working together then work done by them in 1 hr is
  (1/10)+(1/12)= 11/60
  
  to do 11/60 B&C require = 1 hr
  to do 33/60 B&c require = 3 hrs
• 10 years agoHelpfull: Yes(1) No(8)
• there is a slight mistake in this question i.e"A left the work 2 hours before the completion of the work"
• 10 years agoHelpfull: Yes(1) No(1)
• B&C TAKE 2HOURS TO COMPLETE THE REMAINING WORK
  TAKE LCM OF 8,10,12 SO WE GET TOTAL UNITS OF WORK AS 120UNITS
  SO
  A---120/8=15UNITS/HR
  B----120/10=12UNITS/HR
  C-----120/12=10UNITS/HR
  THEY WORK TOGETHER FOR 2HOURS SO TOTAL WORK COMPLETED WAS 15*2+12*2+10*2=74UNITS
  REMAINING WORK=120-74=44UNITS
  SO B=12UNITS/HR
  C=10UNITS/HR
  ---------------
  B&C=22UNITS/HR so to complete r.w i.e 44units they will take 2hours
• 10 years agoHelpfull: Yes(1) No(3)
• 1/8+1/10+1/12=37/120(combine 1 hour work)
  all tree worked for 2 hours so
  work done in 2 hour=74/120=37/60
  Remaining work=23/60
  B and C 1 hour work =1/10+1/12=11/60
  (23/60)/(11/60)=23/11 hour
• 10 years agoHelpfull: Yes(0) No(0)
• 2.09 hours
• 10 years agoHelpfull: Yes(0) No(0)
• 23/11 hrs.
• 10 years agoHelpfull: Yes(0) No(0)