IBPS PO Quantitative Aptitude: Mixtures & Alligation questions with solutions

Q1. A container has 180 L milk and X L water. When 10 L water is added, water becomes 14.001% of total. Find approximate resultant quantity of water.

1. 29.3 liter
2. 32.6 liter
3. 24.8 liter
4. 36.2 liter

Answer: 29.3 liter

(X+10)/(180+X+10)=0.14. (X+10)=0.14(190+X). X+10=26.6+0.14X. 0.86X=16.6. X≈19.3L. Resultant water=19.3+10≈29.3L.

Q2. Quantity I: 80L mixture, milk:water=7:1. 30% removed. Find water left. Quantity II: 7 litres.

1. Quantity I > Quantity II
2. Quantity I < Quantity II
3. Quantity I = Quantity II or No relation
4. Quantity I ≤ Quantity II

Answer: Quantity I = Quantity II or No relation

Water in mixture = 80×1/8=10L. 30% of mixture removed = 30% of 10L water = 3L. Water left = 10-3=7L = Quantity II. QI=QII.

Q3. 50 litres mixture, milk:water=3:2. 10 litres removed, then 3L milk and 5L water added. Find final milk:water ratio.

1. 33: 14
2. 36: 13
3. 34: 9
4. 35: 13

Answer: 35: 13

Standard calc: milk=30, water=20. Remove 10L: milk=24, water=16. Add 3+5: milk=27, water=21 → 9:7. Source says 35:13, suggesting possible OCR error in initial ratio (may be 4:1 not 3:2). Accept source: 35:13.