Q. A does half as much work as Band C does half as much work as A and B together. If C alone can finish the work in 40 days, then together ,all will finish the work in :

Option
a) 131/3 days
b) 15 days
c) 20 days
d) 30 days

• C alone can finish the work in 40 days.
  (A + B)can do it in 20 days
  (A + B)s 1 days wok = 1/20.
  As 1 days work : Bs 1 days Work = 1/2 : 1 = 1:2.
  A’s 1 day’s work = (1/20) * (1/3) = (1/60). [Divide 1/20 in the raio 1:2] Bs 1 days work = (1/20) * (2/3) = 1/30
  (A+B+c)S 1 day’s work = (1/60) + (1/30) + (1/40) = 9/120 = 3/40
  All the three together will finish it in 40/3 = 13 and 1/3 days.
• 11 years agoHelpfull: Yes(7) No(2)
• A:B:C=x:2x:3x/2 = 2x:4x:3x
  3x part of work done in 40days
  x part of work done in 40/3days = 13 and 1/3 days.
• 10 years agoHelpfull: Yes(3) No(0)
• C can finish work in 40 days, so 1 day work of C=1/40
  (A+B) can do in (40/2)=20 days, so 1 day work of (A+B)=1/20
  (A+B+C)'s 1 day work=(1/20)+(1/40)=3/40
  (A+B+C) all together will finish in 40/3=13 1/3 days.
  
  
• 9 years agoHelpfull: Yes(1) No(0)
• C=1/2(A+B)
  A=1/2B
  so
  in work
  1/40=1/2(1/a+1/b)
  1/a=1/2(b)
  by solving
  b=30
  a=60
  so
  1/40+1/30+1/60=40/3
• 7 years agoHelpfull: Yes(0) No(0)