Question

The price of high grade milk is Rs.40 per litre and that of low grade milk is Rs.30 per litre. In what ratio they should be mixed so that the resultant mixture has a price of Rs.36 per litre?

• A. 3:2
• B. 5:4
• C. 4:3
• D. 2:1

Answer 1

The Correct Option is A

Milk Mixture Calculation Using Alligation 

Step 1: Define the Quantities and Prices

Let the quantities of high-grade milk and low-grade milk be x and y respectively. We are given the following prices:

• Price of high-grade milk: Rs. 40 per litre
• Price of low-grade milk: Rs. 30 per litre
• Price of the resultant mixture: Rs. 36 per litre

Step 2: Calculate the Differences Using Alligation

We calculate the difference between the prices of the two types of milk and the desired price:

• Difference 1: 40 − 36 = 4
• Difference 2: 36 − 30 = 6

Step 3: Find the Ratio of Quantities

Now, we find the ratio of the quantities of the two types of milk:

\[ \frac{\text{Difference 1}}{\text{Difference 2}} = \frac{4}{6} = \frac{2}{3} \]

Step 4: Calculate the Required Ratio

The required ratio of high-grade milk to low-grade milk is the inverse of this ratio:

\[ \text{Ratio of high-grade milk to low-grade milk} = 3 : 2 \]

Final Answer:

The correct answer is (a) 3:2.