)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.

• total time taken by B & C will be 23/11 hrs.
• 11 years agoHelpfull: Yes(46) No(7)
• total work done by A+B+C in 1 hr = 37/60
  remaining work = 23/60
  total work done by B+C in 1 hr = 11/60
  total work done by B+C in y hr = 23/60
  
  y=23/11
  
  
• 11 years agoHelpfull: Yes(32) No(18)
• (a+b+c) 2 hr's work=2(1/8+1/10+1/12)=74/120
  so remainig work =46/420
  now time taken by (b+c) is ((46/120)*(60/11))=23/11 hrs
• 11 years agoHelpfull: Yes(31) No(3)
• ans is 45/11
  let B & C together work=T
  2/8+(T/10)+(T/12)=1
  solve it...den u get
  45/11
  
  another way:
  let B n C together work=T
  ((2/8)+(2/10)+(2/12))+((t-2)/10+(t-2)/12))=1
  solve it,,,,u get
  45/11
• 11 years agoHelpfull: Yes(11) No(3)
• work done by A in 1 hr=1/8 ...so work done by A in 2hrs=1/8*2=1/4
  remaining work=1-1/4=3/4.
  Work done by B and C in 1hr=(1/10+1/12)=11/60
  so 3/4 work is done in= 3/4*60/11= 45/11hrs
• 11 years agoHelpfull: Yes(9) No(12)
• This is a lengthy process.
  Total time taken=2+23/11=45/11 hrs.
• 11 years agoHelpfull: Yes(5) No(12)
• A's 1 hours's work =1/8
  B's 1 hour's work = 1/10
  c's 1hour's work =1/12
  
  (A + B+ C)'s 1 hour work = 1/8 + 1/10 + 1/12
  (A + B+ C)'s 2 hour work =( 1/8 + 1/10 + 1/12)*2= 74/120
  after a leaves remaining work need to be done by b and c is 46/120
  46/120 =(1/10 + 1/12)*t
  t=approz 2 hours
  15 20 60
  
  (A + B)'s 4 day's work = ( 7 x 4 ) = 7 .
  60 15
  
  Therefore, Remaining work = ( 1 - 7 ) = 8 .
  15 15
• 11 years agoHelpfull: Yes(3) No(15)
• effective rate of work A+B+C =1/8+1/10+1/12=37/120.so in 2 hours work completed by the three is 37/120*2=37/60.The remaining work is 1-37/60 that is 23/60. now only B and C are working together so 1/10+1/12 = 11/60 is the rate of work. So time taken is 23/60(work remaining)/(11/60)= 2.09 hours approximately
• 10 years agoHelpfull: Yes(1) No(0)