Alligation or Mixture problems
An alloy is made by mixing metal A costing Rs 2000/kg and metal B costing Rs 400/kg in the ratio A:B = 3:1. What is the cost (in Rs) of 8 kilograms of this alloy?
Let the price of the mixed variety be Rs. x per kg. By rule of alligation, we have: Cost of 1 kg of Type 1 rice Cost of 1 kg of Type 2 rice Rs. 15 Mean Price Rs. x Rs. 20 (20 - x) (x - 15) ∴ (20 - x) = 2 (x - 15) 3 ⟹ 60 - 3x = 2x - 30 ⟹ 5x = 90 ⟹ x = 18.
As given equal amounts of alloys are melted, let it be 1 kg. Required ratio of gold and silver = 5 13 + 5 8 8 13 + 3 8 = 105 103 . Hence, ratio of gold and silver in the resulting alloy = 105/103.
Rate of rice of quantity 280 kg = Rs. 15.60/kg Rate of rice of quantity 120 kg = Rs. 14.40/kg He want to earn a profit of Rs. 10.45/kg Rate of Mix to sell to get profit of 10.45 = 280 x 15 . 60 + 120 x 14 . 40 280 + 120 + 10 . 45 4368 + 1728 400 + 10 . 45 = > 15 . 24 + 10 . 45 = 25 . 69