In a mixture of milk and water, the ratio of milk to water is 7:3 . If the total mixture is 120 litres , how many litres of water must be added to the - Quantitative Aptitude MCQ Practice Test 2026 | ExamTest.live

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In a mixture of milk and water, the ratio of milk to water is 7 : 3 . If the total mixture is 120 litres, how many litres of water must be added to the mixture so that the ratio of milk to water becomes 3 : 2 ?

Solution & Step-by-step Explanation

Initial total volume of the mixture = 120 litres . Initial ratio of milk to water = 7 : 3 . Quantity of milk = \frac{7}{7 + 3} \times 120 = \frac{7}{10} \times 120 = 84 litres Quantity of water = 120 - 84 = 36 litres Let the quantity of water to be added be x litres . The new ratio of milk to water becomes 3 : 2 : \frac{84}{36 + x} = \frac{3}{2} Cross-multiplying to solve for x : 2 \times 84 = 3 \times (36 + x) 168 = 108 + 3 x 3 x = 168 - 108 3 x = 60 ⟹ x = 20 litres

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In a mixture of milk and water, the ratio of milk to water is 7 : 3 . If the total mixture is 120 litres, how many litres of water must be added to the mixture so that the ratio of milk to water becomes 3 : 2 ?

25 litres

12 litres

20 litres

16 litres

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