Multiple choice

Prachi purchased 32 litre of milk at Rs. 45 per litre. How much water must be added to milk so that cost of milk reduces to Rs. 40 per litre ? प्राची ने 32 लीटर दूध 45 रुपये प्रति लीटर दर पर खरीदा। दूध में कितना पानी मिलाया जाना चाहिए ताकि दूध की लागत रु 40 प्रति लीटर हो जाए ?

  1. 6 litre

  2. 8 litre

  3. 12 litre

  4. 4 litre

  5. None of these इनमें से कोई नहीं
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cost of 32 litres milk = 32 × 45 = Rs. 1440. When x litres water is added, total quantity becomes (32 + x) litres but cost remains Rs. 1440. New cost per litre = 1440/(32+x) = 40. Solving: 1440 = 40(32 + x), 1440 = 1280 + 40x, 160 = 40x, x = 4 litres. Key insight: adding water changes quantity but not total cost.

Keep practicing — related questions