In what ratio must rice costing ₹53 per kg be mixed with rice costing ₹65 per kg, so that the mixture is worth ₹55 per kg?

💡 Solution & Explanation

Use alligation: the cheaper part : the dearer part = (dearer price − mixture price) : (mixture price − cheaper price) = (65 − 55) : (55 − 53) = 10 : 2, which simplifies to 5 : 1. Check: mixing in that ratio gives an average of ₹55 per kg. Writing the differences the other way round is the most common mistake.