Mixtures and Alligation Questions

Multiple choice
  1. 120

  2. 80

  3. 48

  4. 90

  5. 180

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let original solution be 5x (milk 3x, water 2x). After adding 50% water: 7.5x total (milk 3x, water 4.5x). Removing 30L leaves milk 3x-(12/7.5)x and water 4.5x-(18/7.5)x. Adding 30L water gives final ratio 3:7. Solving gives 3x=48L.

Multiple choice
  1. 12 %

  2. 15 %

  3. 17 %

  4. 20 %

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Initial: 5L of 20% alcohol = 1L alcohol + 4L water. Removing 2L removes 0.4L alcohol (20% of 2L), leaving 0.6L alcohol in 3L solution. Adding 2L water gives 0.6L alcohol in 5L total. Strength = 0.6/5 = 0.12 = 12%. Key insight: removal is proportional to concentration.

Multiple choice
  1. 144 liter/लीटर

  2. 188 liter/लीटर

  3. 248 liter/लीटर

  4. 288 liter/लीटर

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the initial solution quantity be x liters. Initial milk = 0.36x. After adding 72L milk: (0.36x + 72)/(x + 72) = 0.52. Solving: 0.36x + 72 = 0.52x + 37.44, so 0.16x = 34.56 and x = 216. Final quantity = 216 + 72 = 288L. Option D is correct.

Multiple choice
  1. 3 : 1

  2. 5 : 4

  3. 7 : 9

  4. 4 : 5

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the mixtures be combined in ratio x:y. Milk from mixture 1 is (7/10)x, from mixture 2 is (2/5)y. Total milk = (7/10)x + (2/5)y. Total volume = x + y. We need milk:water = 5:3, so milk is 5/8 of total. Setting up: (7x/10 + 2y/5)/(x+y) = 5/8. Cross-multiplying: 8(7x/10 + 2y/5) = 5(x+y). Solving: 28x/10 + 16y/10 = 5x + 5y. This gives 28x + 16y = 50x + 50y, or -22x = 34y, which gives x:y = 3:1 approximately. Verification with x=3, y=1 gives milk fraction = (21/10 + 2/5)/4 = 23/40 = 0.575 = 5/8.

Multiple choice
  1. 60

  2. 80

  3. 140

  4. 65

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Initial mixture has A:B = 3:4. Let quantities be 3x and 4x, total = 7x. When 7 liters drawn, proportion removed: A removed = 3x/7x × 7 = 3, B removed = 4x/7x × 7 = 4. Remaining: A = 3x - 3, B = 4x - 4. After adding 7 liters of A: new A = 3x - 3 + 7 = 3x + 4, new B = 4x - 4. New ratio A:B = (3x + 4):(4x - 4) = 16:19. Cross-multiplying: 19(3x + 4) = 16(4x - 4), giving 57x + 76 = 64x - 64, so 140 = 7x, x = 20. Initial B = 4x = 80 liters. This matches option B.

Multiple choice
  1. 240 litre

  2. 175 litre

  3. 360 litre

  4. 300 litre

  5. None of these

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Let initial quantity be Q. Milk = 87.5% of Q. After removing 50L and adding 30L water, new quantity = Q - 20L. Milk remains 0.875Q - 43.75L. This equals 80% of (Q - 20L). So 0.875Q - 43.75 = 0.8Q - 16, giving 0.075Q = 27.75, so Q = 370L. Since 370L is not among options A-D, the answer is E (None of these).

Multiple choice
  1. 24 litre/लीटर

  2. 30 litre/लीटर

  3. 26 liter/लीटर

  4. 54 litre/लीटर

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let milk=5x, water=3x. After adding 6L water: milk=5x, water=3x+6. New ratio 5x:(3x+6) = 5:4. Cross-multiplying: 20x = 15x+30, so 5x=30, x=6. Initial milk = 5×6 = 30L.

Multiple choice
  1. 12 litre/लीटर

  2. 15 litre/लीटर

  3. 18 litre/लीटर

  4. 20 litre/लीटर

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using alligation: milk cost Rs 25/L, target price Rs 22/L (effectively water at Rs 0/L). Ratio milk:water = (22-0):(25-22) = 22:3. For 88L milk, water = 88 × 3/22 = 12L. Total mixture = 100L at Rs 22/L.

Multiple choice
  1. 32.5 kg.

  2. 37.5 kg.

  3. 42.5 kg.

  4. 45 kg.

  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alloy has Cu:Al = 7:4, so Al is 4/11 of total alloy. 12% is destroyed, so remaining is 88%. If 12 kg Al is in weapon: original Al needed = 12/0.88 = 13.636 kg. Since Al is 4/11 of total, total alloy = 13.636 × (11/4) = 37.5 kg. Option B is correct. Account for loss first, then use ratio.

Multiple choice
  1. 137 : 537

  2. 25 : 63

  3. 89 : 191

  4. 55 : 87

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mixture 1 (1:3): water=1/4, milk=3/4. Mixture 2 (2:3): water=2/5, milk=3/5. Mixture 3 (2:5): water=2/7, milk=5/7. Mixed in 1:2:3 ratio: Total water = 1*(1/4) + 2*(2/5) + 3*(2/7) = 1/4 + 4/5 + 6/7 = 267/140. Total milk = 1*(3/4) + 2*(3/5) + 3*(5/7) = 3/4 + 6/5 + 15/7 = 573/140. Ratio = 267:573 = 89:191.

Multiple choice
  1. 91 : 9

  2. 81 : 19

  3. 80 : 20

  4. 90 : 10

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

After first replacement: wine = 100 - 10 = 90, water = 10. Ratio 90:10. When 10L drawn from mixture, wine removed = 10 × (90/100) = 9L, water removed = 10 × (10/100) = 1L. Remaining: wine = 90 - 9 = 81L, water = 10 - 1 = 9L. Adding 10L water: wine = 81L, water = 9 + 10 = 19L. Final ratio is 81:19. This uses mixture alligation principles.

Multiple choice
  1. $2 : 3$
  2. $5 : 8$
  3. $3 : 5$
  4. $3 : 8$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The mixture initially has 450 liters with 30% soda (135 liters) and 70% water (315 liters). After adding 45 liters of water, we have 135 liters soda and 360 liters water. The ratio is 135:360, which simplifies to 3:8 (divide both by 45). Option D is correct. Options A (2:3), B (5:8), and C (3:5) don't match this calculation.

Multiple choice
  1. $118 : 145$
  2. $221 : 145$
  3. $445 : 661$
  4. $661 : 445$
  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Initial salt = 8500 × 0.65 = 5525 litres. Initial water = 8500 - 5525 = 2975 litres. After adding 650 litres water: new water = 2975 + 650 = 3625 litres. Ratio salt:water = 5525 : 3625. Dividing by 25: 221 : 145.