3
Q:

# The average of a set of whole numbers is 27.2. when the 20% of the elements are eliminated from the set of numbers then the average become 34. The number of elements in the new set of numbers can be :

 A) 27 B) 35 C) 52 D) 63

Explanation:

only (c) is correct since it is divisible by 4.

Let the original number of element  be x then the new no.of elements wil be

$\inline&space;\frac{4x}{5}=K$

So K must be divisible by 4

Since,      x =  $\inline&space;\frac{K&space;\times&space;5}{4}$

Q:

What percent is 120 of 85 ?

 A) 133.33 % B) 141.17 % C) 145.54 % D) 139.29 %

Explanation:

px85/100 = 120

=> p = 12000/85 = 141.17 %

1 5
Q:

A number increased by 30% gives 390. The number is

 A) 180 B) 300 C) 480 D) 260

Explanation:

Let the number be 'N'
Given N + 30N/100 = 390
=> 130N/100 = 390
=> N = 390 x 10/13
=> N = 300.

1 7
Q:

If 25% of a number is subtracted from a second number, the second number reduces to its four-sixth. What is the ratio of the first number to the second number  ?

 A) 4:3 B) 2:3 C) 3:2 D) 5:3

Explanation:

Let the numbers be p & q

q-p/4 = 4q/6

=> q-4q/6 = p/4

=> 2q/6 = p/4

=> p/q = 4/3

2 35
Q:

A number, when 35 is subtracted from it, reduces to its 80 percent. What is four - fifth of that number  ?

 A) 175 B) 140 C) 135 D) 95

Explanation:

x - 35 = 80x/100

=> x = 175

=> 4x/5 = 4x175/5 = 140.

3 43
Q:

5% people of a village in India died by dengue, 15% of the remainder left the village on account of fear. If now the population is reduced to 3553, how much was it in the beginning ?

 A) 4400 B) 3100 C) 2800 D) 5600