4. A,B and C can do some work in 36 days.A and B together do twice as much work as C.A and C together do thrice as much work as B.Time taken by C alone to complete the work :
(a)72 (b)120 (c)96 (d)108

• 1/a +1/b +1/c =1/36..eq1
  1/a +1/b =2/c ..eq2
  1/a +1/c =3/b ..eq3
  eq1-eq2
  1/c =1/36 - 2/c
  3/c =1/36
  c=108...ans
• 11 years agoHelpfull: Yes(19) No(0)
• A+B+C=1/36 ...... 1
  A+B=2C ........ 2
  A+C=3B
  sub 2 in 1
  2C+C=1/36 therefore C=1/108 and hence 108 is d ans
  
• 11 years agoHelpfull: Yes(8) No(0)
• 1/a+1/b+1/c=1/36--->(1)
  1/a+1/b=2/c--->(2)
  1/a+1/c=3/b--->(3)
  sub (2) in (1) , we get
  3/c=1/36
  c=36*3=108
  ans is c=108
  
• 8 years agoHelpfull: Yes(1) No(0)
• 1/a+1/b+1/c=1/36
  1/a+1/b=2/c
  1/a+1/c=3/c
  now after solving above 2 equation
  1/a=5/4c
  1/b =3/4c
  now
  5/4c+3/4c+1/c=1/36
  c=108
• 8 years agoHelpfull: Yes(1) No(0)
• ans=108;
  a+b+c=1/36 work per day .given that:a+b=2cand a+c=2b.put a+b=2c in a+b+c=1/36;
  so c=1/108 work per day, so c complete in 108day;
• 8 years agoHelpfull: Yes(1) No(0)
• Let the equations turn out to be...
  
  A+B+C=36......(1)
  A+B=2C..........(2)
  A+C=3B...........(3)
  
  put eq (2) in eq (1)
  
  2C+C=1/36
  3C=1/36
  C=108...
• 8 years agoHelpfull: Yes(1) No(0)
• A+B+C=1/36 ->eq1
  A+B=2C ->eq2
  A+C=3B ->eq3
  eq2 in eq1
  2C+C=1/36
  3C=1/36
  C=1/108..........ans is (d)
  
• 8 years agoHelpfull: Yes(0) No(0)
• by solving eqns we get 12b=36 which implies b can do work in 36*12 days and we get 4b=c so c can do same work in 36*12/4=108
• 8 years agoHelpfull: Yes(0) No(0)
• answer will be 108.
• 8 years agoHelpfull: Yes(0) No(0)
• (1/a)+(1/b)+(1/c)=1/36
  (1/a)+(1/b)=2/c
  c=108 days
• 8 years agoHelpfull: Yes(0) No(0)
• 1/A+1/B+1/C=1/36...Eq.(1)
  1/A+1/B=1/2C...Eq.(2)
  1/A+1/C=1/3B
  Substitute Eq.(1) in Eq.(2)
  Then we can find that C can complete the work in 108 days...
  then 1/2C+1/C
• 8 years agoHelpfull: Yes(0) No(0)
• 108....a+b +c-1/36
  a+b-2c....equation 1
  a+c-3b .... equation 2 getting d values of a and c
  put in equation a+b+c=1/36
  
• 8 years agoHelpfull: Yes(0) No(0)
• option d..as a+b=2c; time and work are inversly proportional....let c can do the work in 2x days and a+b can do the work in x days. we know a+b+c=36 days ...one day work of a+b+c=1/36;one day work of a+b=1/x;c=1/2x;a+b+c=1/36;(1/2x)+(1/x)=1/36;then x=54......by this 108
  
• 8 years agoHelpfull: Yes(0) No(0)
• Very simple-
  1/a+1/b+1/c=1/36 -eqn 1
  1/a+1/b=2/c -eqn 2
  1/a+1/c=3/c (no use)
  now after equating eqn2 in eqn1, we have
  2/c+1/c=1/36
  On furthure solving,
  3/c = 1/36
  So, c = 3*36
  C=108
  
  No need of equation 2
• 8 years agoHelpfull: Yes(0) No(0)