model 7 marks scored in examinations Section-Wise Topic Notes With Detailed Explanation And Example Questions

Answer: (d)

Let the marks obtained by first student be x.

Marks obtained by second student = x + 9

Sum of their marks = 2x + 9

As given, x + 9 = 56% of (2x + 9)

x + 9 = $56/100 × (2x + 9)$

$x + 9 = 14/25 × (2x + 9)$

25x + 225 = 28x + 126

3x = 225 – 126 ⇒ $x = 99/3 = 33$

Marks obtained are 42 and 33.

Answer: (b)

A = 360;

B = ${360 × 100}/90 = 400$

C = ${400 × 100}/125 = 320$

D = ${320 × 100}/80 = 400$

Required percentage = $400/500 ×100 = $80%

Answer: (a)

Let the maximum marks in the examination = x.

According to the question,

${40x}/100 - {30x}/100 = 50$

${10x}/100 = 50$

$x = {50 × 100}/10 = 500$

Using Rule 22,

m = 30%, n = 40%, p = 25 and q = 25

Maximum marks = $100/{(n - m)} × (p + q)$

= $100/{(40 - 30)} × (25 + 25) = 500$

Answer: (a)

Let the total number of students = 100

Number of students who failed in Hindi or English or both

= 52 + 42 – 17 = 77

Number of students who passed in both subjects

= 100 – 77 = 23%

Required percentage = 23

Using Rule 23,

a = 52%, b = 42%, c = 17%

Passed candidates = 100 – (52 + 42 – 17)

= 100 – (94 – 17) = 100 – 77 = 23%

Answer: (a)

Let the maximum marks be x.

According to question,

20% of x + 5 = 30% of x –20

(30 –20)% of x = 25

x = ${25 × 100}/10 = 250$

Passing marks = 20% of 250 + 5 = 55

% Passing marks = $55/250 × 100 = 22%$

Using Rule 22,

Here, m = 30%, n = 20%, p = 5 and q = 20

Maximum marks = $100/\text"(n - m)" × (p + q)$

= $100/{(30 - 20)} × (5 + 20)$

= ${100 × 25}/10 = 250$

Passing marks = 20% of 250 + 5 = 55

% of passing marks = $55/250 × 100$ = 22%