Model 10 Percentage With Allegations & Mixture Section-Wise Topic Notes With Detailed Explanation And Example Questions

Answer: (c)

Sugar in original solution

= ${75 × 30}/100$ = 22.5gm

Let x gm of sugar be mixed.

${22.5 + x}/{75 + x} × 100 = 70$

2250 + 100x = 75 × 70 + 70x

2250 + 100x = 5250 + 70x

30x = 5250 – 2250 = 3000

x = $3000/30$ = 100 gm

Answer: (d)

In 300 gm of solution,

Sugar = ${300 × 40}/100 = 120gm.$

Let x gm of sugar be mixed.

According to the question,

${120 + x}/{300 + x} =1/2$

240 + 2x = 300 + x

2x – x = 300 – 240 ⇒ x = 60 gm.

Answer: (a)

Let x ml of water be added.

${20 + x}/{100 + x} × 100$ = 50

40 + 2x = 100 + x ⇒ x = 60 ml

Answer: (d)

In 200 litres of mixture,

Quantity of milk = 85 100 ´ 200 = 170 litres

Quantity of water = 30 litres

Let the quantity of additional milk added be x litres.

According to the question,

${170 + x}/{200 + x} × 100 = 87.5$

(170 +x) × 100 = 17500 + 87.5x

100x – 87.5x = 17500 – 17000

12.5x = 500

x = $500/12.5$ = 40 litres