Respuesta :

mhanifa

Answer:

13 l of 15%, 13 l of 25%, 26 l of 70%

Step-by-step explanation:

solutions:

  • 15%, 25% and 70%

final solution:

  • 52 l of 45%

This includes 0.45*52l= 23.4 l acid

Let's assume:

  • amount of 15% solution= x
  • amount of 25% solution= y
  • amount of 70% solution= z
  • and we have z=2y

so there are 2 equation:

  • x+y+z=52
  • 0.15x+0.25y+0.7z=23.4

or

  • x+y+2y= 52 ⇒ x+3y= 52 ⇒ x= 52- 3y
  • 0.15x+0.25y+1.4y=23.4
  • 0.15x+1.65y=23.4
  • 0.15*(52-3y)+1.65y=23.4
  • 7.8-0.45y+1.65y=23.4
  • 1.2y=23.4-7.8
  • 1.2y= 15.6
  • y=15.6/1.2
  • y= 13 l

--------

  • x= 52- 3*13= 13 l
  • z= 2y= 2*13= 26 l

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