Price of the mixture — Aptitude Question
Price of the mixture: 15 kg of sugar at ₹40 per kg is mixed with 25 kg at ₹32 per kg. Answer and worked solution on CodeKairo.
- Topic: Mixtures & Alligation
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 60 seconds
Question
15 kg of sugar at ₹40 per kg is mixed with 25 kg at ₹32 per kg. What is the price per kg of the mixture?
Options
- ₹34
- ₹35
- ₹36
- ₹38
Show the answer and the worked solution
Correct answer: B. ₹35
Worked solution
- Cost = 15 × 40 + 25 × 32 = 600 + 800 = ₹1,400.
- Weight = 40 kg.
- Price = 1,400 ÷ 40 = ₹35 per kg.
Answer: ₹35.
The idea
A weighted average, so it leans towards the larger quantity — here towards ₹32, giving ₹35 rather than the plain mean of ₹36.
Shortcut. Quantities 15 : 25 = 3 : 5, so the price is 3/8 of the way from ₹32 to ₹40: 32 + 3 = ₹35.
Common trap. ₹36 — the plain mean of ₹40 and ₹32, which ignores that there is more of the cheaper sugar.