How many litres of a 90% concentric acid needs to be mixed with 75% concentric acid so as to get 30 litre of 78% concentric acid?

• x*90+(30-x)*75=30*78
  so x=6
  
• 9 years agoHelpfull: Yes(12) No(0)
• first you have to write formulae
  
  ax=a1n1+a2n2/(n1+n2)
  where ax is mixed percentage
  a1 is first solution percentage
  a2 is second solution percentgage
  
  78=(90n1+75n2)/(n1+n2)
  
  then we get n1/n2=1/4
  we have to find out in 30 ltrs
  1/1+4(30)=6
  Ans::: 6ltrs
  
• 9 years agoHelpfull: Yes(6) No(4)
• Using alligation we get the ratio of 75% :90% is (90-78):(78-75)=4:1
  total solution is 30lit
  then the solution mix according to the ratio.so 90% solution is mix=(30*1/5)= 6lit
• 9 years agoHelpfull: Yes(6) No(0)
• Use weighted ratio rule
  90a+75b/a+=78
  After solving 4a=b
  Given a+b=30.......eq 1
  Put 4a=b in eq 1
  5a=30
  A=6
• 9 years agoHelpfull: Yes(3) No(1)
• let x litres 90%..then total mix=30..therefore..75%will b (30-x)litres..forming eqn we get..
  90*x+(30-x)*75=30*78...solving..we get x=6litres
• 9 years agoHelpfull: Yes(3) No(0)
• 90-78=12
  75-78=3
  3/12=1/4 so 4 liters should be added
• 9 years agoHelpfull: Yes(2) No(2)
• Let n1 liters of 90% concentration has to be mixed with n2 liters of 75% concentration to get 78% concentration solution. Using weighted average formula ax=n1×a1+n2×a2n1+n2
  78=n1×90+n2×75n1+n2
  n1n2=14
  by dividing 30 in the ratio 1:4 we get 6 : 24. So we need 6 liters.
• 9 years agoHelpfull: Yes(2) No(0)
• (90a+75b)/(a+b)=78
  a:b=1:4
  then (1/5)*30=6litr
• 9 years agoHelpfull: Yes(2) No(1)
• Let n1 liters of 90% concentration has to be mixed with n2 liters of 75% concentration to get 78% concentration solution. Using weighted average formula ax=n1*a1+n2*a2/n1+n2
  78=n1*90+n2*75/n1+n2
  solving we get
  n1:n2=1:4
  so by dividing 30 in the ratio 1:4 we get 6 : 24. So we need 6 liters.
• 9 years agoHelpfull: Yes(1) No(0)
• Answer will be 6ltrs..
  Using alligation method we can easily find out the answer.
  90 75
  /
  /
  78
  /
  /
  (78-75)=3 (90-78)=12
  so,the required ratio is =3:12=1:4
  so the amount of 1st acid become =30*1/(1+4)=6ltrs.
• 9 years agoHelpfull: Yes(1) No(0)
• 0.9x+.75y = 23.4 (30lit of 78%)--------------- Eq1
  x+y = 30 * 0.9
  0.9x+0.9y = 27 -------------------------- Eq 2
  Solve Equ 1 & 2
  Y = 24
  sub y in Eq 1
  thus X = 5.4litres
  
  
• 8 years agoHelpfull: Yes(1) No(0)
• hey its smashing amaan ,do it by aligation 90 --78--75 then you got ration of 1 : 4 so you need to mix 6 litre of conc acid in 24 litr con acid
  
• 9 years agoHelpfull: Yes(0) No(0)