Percentage with Explanation

Q1. 10% of the villagers have died of dengue. A panic situation arises in which 25% of the remaining villagers left the village. The population is then reduced to 4050. What is the original number of villagers?

Answer- Option D

Explanation-

Let the toatl number of original inhabitants be x
Then, (100 - 25)% of (100 - 10)% of x = 4050

75 100

*

90 100

* x

= 4050

x = 6000

Q2. The total number of girls and boys in a campus are 150. If the number of boys is x, then the number of girls becomes x% of the total number of students. How many boys are there in the school?

Answer- Option B

Explanation-

We have : x + x% of 150 = 150

x +

x 100

* 150

= 150

x = 60

Q3. If the price of an Apple was decreased by 10%, then the number of apples sold increased by 30%. Find the effect on the total revenue?

Answer- Option A

Explanation-

Let the price of the product be Rs. 100 and let original sale be 100 pieces.
Then, Total Revenue = Rs. (100 x 100) = Rs. 10000
New Revenue = Rs. (90 x 130) = Rs. 11700.
Increase in revenue

=

1700 10000

x 100

% = 17%

Q4. In a survey, 40% houses contained two or more people. Of those houses containing only one person, 25% were having only a male. Determine the percentage of all houses that contain exactly one female and no males?

Answer- Option C

Explanation-

Let the total number of houses be x. Then,
Number of houses having one female only = (100 - 25)% of (100 - 40)% of x

=

75 100

*

60 100

* x

=

9 20

x

Required Percentage

=

9x 20

*

1 x

* 100

% = 45%

Q5. In an election between two candidates, 75% of the voters cast their votes, out of which 2% of the votes were declared invalid. One of the candidates got 9261 votes which were 75% of the total valid votes. What is the total number of votes enrolled in this election?

Answer- Option B

Explanation-

Let the total number of votes enrolled be x. Then,
Number of votes cast = 75% of x. Valid votes = 98% of (75% of x)
75% of [98% of (75% of x)] = 9261

75 100

*

98 100

*

75 100

* x

= 9261

x = 16800

Q6. In an entrance test in City P, 6% candidates got selected from the total appeared candidates. City Q had an equal number of candidates appeared, and 7% candidates got selected with 80 more candidates got selected than P. Find the number of candidates appeared in the test from each city?

Answer- Option C

Explanation-

Let the number of candidates appeared from each city be x.
Then, 7% of x - 6% of x = 80
1% of x = 80
x = 80 x 100 = 8000

Q7. 24% of 210 + 88% of 370 - ? = 118

Answer- Option B

Explanation-

Let 88% of 370 + 24% of 210 - x = 118
Then, x =

88 100

* 370

+

24 100

* 210

- 118

x = 325.60 + 50.40 - 118 = 376 - 118 = 258