How many kgs of Basmati rice costing Rs.42/kg should a shopkeeper mix with 25 kgs of ordinary rice costing Rs.24 per kg so that he makes a profit of 25% on selling the mixture at Rs.40/kg

• Let the amount of Basmati rice being mixed be x kgs. As the trader makes 25% profit by selling the mixture at Rs.40/kg, his cost /kg of the mixture = Rs.32/kg.
  
  i.e. (x * 42) + (25 * 24) = 32 (x + 25)
  => 42x + 600 = 32x + 800
  => 10x = 200 or x = 20 kgs.
• 7 years agoHelpfull: Yes(1) No(0)
• As the trader makes 25% profit by selling the mixture at Rs.40/kg, his cost per kg of the mixture = Rs.32/kg.
  
  Step 2:
  C.P of 1 kg of rice of 1st kind = Rs. 42
  C.P of 1 kg of rice of 2nd kind = Rs. 24
  Mean price = Rs. 40
  
  By the rule of alligation, we have:
  
  C.P. of 1kg of C.P. of 1kg of
  
  rice of 1st rice of 2nd
  
  kind (Rs. 42) kind (Rs. 24)
  
  
  
  /
  
  Mean Price
  (Rs. 32)
  
  /
  
  
  
  40 - 24 : 42 - 32
  
  (8) (10)
  
  Let the amount of Basmati rice being mixed be x kgs.
  8:10=x:25 ⇒ (45)=(x25) ⇒ x=20 kgs.
  
  Alternatively:
  Let the amount of Basmati rice being mixed be x kgs.
  As the trader makes 25% profit by selling the mixture at Rs.40/kg, his cost per kg of the mixture = Rs.32/kg.
  
  i.e. (x×42)+(25×24)=32(x+25)
  ⇒ 42x+600=32x+800
  ⇒ 10x=200 ⇒ x=20 kgs.
• 9 years agoHelpfull: Yes(0) No(2)