2 2 6 2 4 5

# PERCENTAGE & RATIO PROPORTION SET11

Q.1 In a group of 15 students 7 read French, 8 read English, while 3 of them read none of these two. How many of them read French & English both?

A) 0

B) 3

C) 4

D) 5

Ans. B
Let circles A & B represent people who read French & English respectively

X = Students who read French
Y = Students who read French & English both
Z = Students who read English
( X + Y + Z) + 3= 15
So, (X + Y + Z) = 15-3
=12
(X+Y) = 7
(Y+Z) = 8
Thus, (X+2Y+Z) =15
Subtracting 1 from 2
Y=15-12
=3

Directions: A publishing firm publishes newspaper A, B & C. In an attempt to persuade advertisers to insert advertisements in these newspapers, the firm sends out the following statements to possible advertisers:
A survey of representative sample of the whole population shows that:
Newspaper A is read by 26%
Newspaper B is read by 25%
Newspaper C is read by 14%
Newspaper A + B are read by 11%
Newspaper B + C are read by 10%
Newspaper A + C are read by 9%
Newspaper C only is read by 00%

A) 1

B) 4

C) 5

D) 6

Ans. C

%age of readers who read all three newspapers is represented by U =
= 5%

Q.3 The %age of readers who read A & B but not C

A) 2

B) 4

C) 5

D) 6

Ans. D

%age of readers who read (A+B) but not C is represented by S =
=6%

Q.4 The %age of readers who read atleast one of the three newspapers is

A) 40

B) 50

C) 60

D) 65

Ans. A

The %age of readers who read atleast one of the three newspapers is represented by P+Q+R+S+T+U+V
= 11+9+0+6+4+5+5
= 40%

EXPLANATION:

Suppose the no. of persons= 100
On the basis of information:
(P+S+U+T) = 26…….(i)
(S+Q+U+V) = 25……(ii)
(T+U+V+R) = 14……(iii)
(S+U) = 11…..(iv)
(U+V) = 10……(v)
(T+U) =09…….(vi)
R =00…….(vii)
From eq. (iii),(vi) & (vii)
(T+U+V+R) = 14
9+V+0 = 14
V = 5
U = 5
From eq.(iii) we have
T+U+V+R = 14
T+5+5+0 = 14
T = 4
From (iv) we have
S =6
From (ii), we have
Q+6+5+5 = 25
Q = 9
P= 11
Q= 9
R= 0
S= 6
T= 4
U= 5
V= 5

Q.5 A student divided a number by 2/3 when he required to multiply by 3/2. Calculate the percentage of error in his result.

A) 1 %

B) 2 %

C) 0 %

D) 4 %

Ans. C

Explanation:
Since 3x / 2 = x / (2 / 3) 