In what ratio must sugar costing ₹46 per kg be mixed with sugar costing ₹74 per kg, so that the mixture is worth ₹53 per kg?

💡 Solution & Explanation

Use alligation: the cheaper part : the dearer part = (dearer price − mixture price) : (mixture price − cheaper price) = (74 − 53) : (53 − 46) = 21 : 7, which simplifies to 3 : 1. Check: mixing in that ratio gives an average of ₹53 per kg. Writing the differences the other way round is the most common mistake.