Alligation or Mixture problems
A grocer buys two kind of rice at Rs. 1·80 and Rs. 1·20 per kg respectively. In what proportion should these be mixed, so that by selling the mixture at Rs. 1·75 per kg, 25 % may be gained?
Ratio of milk and water = 2 : 1Quantity of milk = 60 X 2/3 = 40 litreQuantity of water = 20 litreTo make ratio, 1: 2, we have to double the water that of milkSo, water should be 80 litre.That means 80 ? 20 = 60 litre water to be added.
Here first two varieties of tea are mixed in equal ratio.So their average price = (126 + 135) /2 = Rs. 130.50 Let price of the third variety per kg be Rs. A; then now mixture is formed by two varieties one at Rs. 130.50 per kg and other at Rs. A per kg in the same ratio 2 : 2 i.e, 1 : 1 By the rule of alligation,(A - 153) / (22.50) = 1 ? A ? 153 = 22.50 ? A = Rs. 175.50
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
Initial quantity of copper = 80 100 x 50 = 40 g And that of Bronze = 50 - 40 = 10 g Let 'p' gm of copper is added to the mixture => 50 + p x 90 100 = 40 + p => 45 + 0.9p = 40 + p => p = 50 g Hence, 50 gms of copper is added to the mixture, so that the copper is increased to 90%.
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.
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