Question

In what ratio must water be mixed with milk costing Rs. 32 per litre to obtain a mixture worth Rs. 28 per litre? (Water is free.)

• A. 1 : 8
• B. 1 : 7
• C. 2 : 7
• D. 1 : 6

Hint:

Assume the final mixture is exactly one litre and write a direct cost-balance equation between water and milk instead of using the alligation cross method.

Answer 1

The Correct Option is B

By alligation, water costs 0 and milk costs 32, mean price 28. Ratio of water to milk \(=\frac{32-28}{28-0}=\frac{4}{28}=\frac{1}{7}\), i.e. \(1:7\). Correct option: 1 : 7.