Four litres of phenol is drawn from a can. It is then filled water. Four litres of mixture is drawn again and the bottle is again filled with water. The quantity of phenol now left in the bottle is to that of water is in the ratio 36:13. How much does the bottle hold

• Ans is 28 ltrs. let A is the value. then A-4/4 is the ratio after adding 4 ltrs of water. then (A-4)*r+4*r=(A-4) so r=(A-4)/4. In second addition of water, qty of phenol is ((A-4)*r) & qty of water is (4*r+4). so the final ratio ((A-4)*r)/(4*r+4) = 36/13, after solving with considering the value of r =(A-4)/4 eqn is (13A^2-392A+784=0). And solution of the eqn is 28.
• 12 years agoHelpfull: Yes(0) No(3)
• Amount of liquid left after n operation, if x is the capacity of the container from which y units are taken out each time is
  ⎪ ⎭ ⎪ ⎬ ⎫
  ⎪ ⎩ ⎪ ⎨ ⎧
  ⎟ ⎠ ⎞
  ⎜ ⎝ ⎛ − n x y x 1 units. Here y = 4 n = 2
  49 36
  x 4
  4 1
  2 =⎟ ⎠ ⎞
  ⎜ ⎝ ⎛ −
  49 9
  x 4
  1
  2 =⎟ ⎠ ⎞
  ⎜ ⎝ ⎛ −
  7 3
  x 4 1 − = x = 7 The bottle holds 7 litres
• 7 years agoHelpfull: Yes(0) No(0)