In what ratio must wheat at Rs. 3.20/kg be mixed with wheat at Rs. 2.90/kg so that the mixture be worth Rs. 3/kg?

Step 1: Identify the values

• Higher price wheat = Rs. 3.20 per kg
• Lower price wheat = Rs. 2.90 per kg
• Mean price (desired mixture price) = Rs. 3.00 per kg

Step 2: Apply the Alligation Rule

Cheaper       Mean        Dearer
  2.90         3.00         3.20

  \______________________/ 
         \          /
        0.20      0.10

Step 3: Take the differences diagonally

• Difference between Rs. 3.20 and Rs. 3.00 = Rs. 0.20
• Difference between Rs. 3.00 and Rs. 2.90 = Rs. 0.10

Step 4: Ratio of mixing = 0.20 : 0.10 = 2 : 1

Answer: 2 : 1

To get a mixture worth Rs. 3/kg, wheat at Rs. 3.20/kg and Rs. 2.90/kg must be mixed in the ratio 2:1 (Rs. 2.90 wheat : Rs. 3.20 wheat).

This type of question is commonly seen in quantitative aptitude tests and competitive exams. It tests your understanding of the Alligation and Mixture Rule, which is useful in scenarios involving blending items with different prices or qualities to achieve a desired average.