Interview Q&A / Aptitude

1. ₹10,000 is lent partly at 8% and partly at 12% simple interest. The total interest for one year is ₹960. How much was lent at each rate?

   ₹6,000 at 8% and ₹4,000 at 12%. The overall rate is 960/10,000 = 9.6%. Alligation gives (12 - 9.6) : (9.6 - 8) = 2.4 : 1.6 = 3 : 2.

   IntermediateQuick answer1 min read
2. A milkman buys milk at ₹60 per litre. How much water should he add per litre so that by selling the mixture at ₹60 per litre he makes a 20% profit?

   200 ml per litre (milk : water = 5 : 1). For 20% profit at ₹60, the mixture's cost must be 60 / 1.2 = ₹50 per litre. Alligation of milk (₹60) and water (₹0) about ₹50 gives 50 : 10 = 5 : 1.

   IntermediateQuick answer1 min read