a certain type of mixture is prepared by
brand A at Rs 9 kg with brand B at Rs 4 kg.if the mixture worth is Rs 7 a kg.how many kgs of brand A are needed to make 40kgs of the mixture?

• Ans:24 kg
  Suppose to prepare 1kg of mixture we need x kg of A and y kg of B.
  therefore x+y=1
  now 9x + 4y =7 (for 1 kg of mixture)
  this will give x=3/5 kg and y=2/5 kg for 1 kg of mixture
  for 40 kg of mixture quantity of A required is 40*3/5 = 24kg
• 11 years agoHelpfull: Yes(1) No(0)
• Ans : 24 kg
  Let the mass of brand A used to make 1kg of mixture be x kg.
  Then mass of brand B used in it = 1-x
  Now 9x+4(1-x) = 7 => 5x = 3 => x=3/5
  To make 40kgs of the mixture, we need 40x = 40*3/5 = 24 kgs of brand A
  
• 11 years agoHelpfull: Yes(1) No(0)