model 11 percentage with ratios Section-Wise Topic Notes With Detailed Explanation And Example Questions

Answer: (c)

Let the number of students in school be 100.

Boys ⇒ 60 Girls ⇒ 40

Students who do not hold scholarship :

Boys ⇒ ${60 × 80}/100$ = 48 Girls ⇒ ${40 × 75}/100$ = 30

Required answer = 48 + 30 = 78 i.e., 78%

Answer: (a)

Let the numbers be x and y and x is greater than y.

Then x – y = 45% of (x + y)

x – y = $45/100(x + y)$

x – y = $9/20(x + y)$

20x – 20y = 9x + 9y

20x – 9x = 20y + 9y

11x = 29y

$x/y = 29/11$ or 29 : 11

Answer: (a)

The raised price = $120/100$ of the former price

The householder must now consume $100/120$ of the original amount

The reduction in consumption = $(1 – 100/120)$ of the original consumption = $1/6$ of the original consumption

i.e. 1 : 6

Required percentage = $(20/{100 + 20})×100$

= $20/120×100$ = $100/6$%

Required ratio = 1 : 6

Answer: (a)

Let the third number be 100.

First number = 120; Second number = 150

Required ratio = $120/150$

= $4/5$ or 4 : 5

Answer: (b)

50% of x = 30% of y

${x × 50}/100 = {y × 30}/100$

$x/y = 30/50 = 3/5$ = 3 : 5

Answer: (d)

Let B = 100

According to question,

A is 40% greater than B. ∴ A = 140

B is 20% less than C

⇒ 0.8C = 100∴ C = 125

∴ A : C = 140 : 125 = 28 : 25