Aptitude

Two students appeared at an examination. One of them secured 9 marks more than the other and his marks was 56% of the sum of their marks. The marks obtained by them are:

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Question:
Two students appeared at an examination. One of them secured 9 marks more than the other and his marks was 56% of the sum of their marks. The marks obtained by them are:

[A].

39, 30

[B].

41, 32

[C].

42, 33

[D].

43, 34

Answer: Option C

Explanation:

Let their marks be (x + 9) and x.

Then, x + 9 = 56 (x + 9 + x)
100

25(x + 9) = 14(2x + 9)

3x = 99

x = 33

So, their marks are 42 and 33.

In a certain school, 20% of students are below 8 years of age. The number of students above 8 years of age is of the number of students of 8 years of age which is 48. What is the total number of students in the school?

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Question: In a certain school, 20% of students are below 8 years of age. The number of students above 8 years of age is of the number of students of 8 years of age which is 48. What is the total number of students in the school?
[A].

72

[B].

80

[C].

120

[D].

150

Answer: Option E

Explanation:

Let the number of students be x. Then,

Number of students above 8 years of age = (100 – 20)% of x = 80% of x.

80% of x = 48 + 2 of 48
3
80 x = 80
100

x = 100.

Video Explanation: https://youtu.be/yPfocU6DA2M

In an election between two candidates, one got 55% of the total valid votes, 20% of the votes were invalid. If the total number of votes was 7500, the number of valid votes that the other candidate got, was:

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Question: In an election between two candidates, one got 55% of the total valid votes, 20% of the votes were invalid. If the total number of votes was 7500, the number of valid votes that the other candidate got, was:

[A].

2700

[B].

2900

[C].

3000

[D].

3100

Answer: Option A

Explanation:

Number of valid votes = 80% of 7500 = 6000.

Valid votes polled by other candidate = 45% of 6000

= 45 x 6000 = 2700.
100

A fruit seller had some apples. He sells 40% apples and still has 420 apples. Originally, he had:

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Question: A fruit seller had some apples. He sells 40% apples and still has 420 apples. Originally, he had:
[A].

588 apples

[B].

600 apples

[C].

672 apples

[D].

700 apples

Answer: Option D

Explanation:

Suppose originally he had x apples.

Then, (100 – 40)% of x = 420.

60 x x = 420
100
x = 420 x 100   = 700.
60

Video Explanation: https://youtu.be/-Pv25Do3WwY

A batsman scored 110 runs which included 3 boundaries and 8 sixes. What percent of his total score did he make by running between the wickets?

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Question: A batsman scored 110 runs which included 3 boundaries and 8 sixes. What percent of his total score did he make by running between the wickets?
[A].

45%

[B].

45 5 %
11

[C].

54 6 %
11

[D].

55%

Answer: Option B

Explanation:

Number of runs made by running = 110 – (3 x 4 + 8 x 6)

= 110 – (60)

= 50.

Required percentage = 50 x 100 % = 45 5 %
110 11

Video Explanation: https://youtu.be/X2zTnABqEHU

Gauri went to the stationers and bought things worth Rs. 25, out of which 30 paise went on sales tax on taxable purchases. If the tax rate was 6%, then what was the cost of the tax free items?

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Question: Gauri went to the stationers and bought things worth Rs. 25, out of which 30 paise went on sales tax on taxable purchases. If the tax rate was 6%, then what was the cost of the tax free items?

[A].

Rs. 15

[B].

Rs. 15.70

[C].

Rs. 19.70

[D].

Rs. 20

Answer: Option C

Explanation:

Let the amount taxable purchases be Rs. x.

Then, 6% of x = 30
100
x = 30 x 100 = 5.
100 6

Cost of tax free items = Rs. [25 – (5 + 0.30)] = Rs. 19.70

The population of a town increased from 1,75,000 to 2,62,500 in a decade. The average percent increase of population per year is:

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Question:
The population of a town increased from 1,75,000 to 2,62,500 in a decade. The average percent increase of population per year is:

[A].

4.37%

[B].

5%

[C].

6%

[D].

8.75%

Answer: Option B

Explanation:

Increase in 10 years = (262500 – 175000) = 87500.

Increase% = 87500 x 100 % = 50%.
175000
Required average = 50 % = 5%.
10

Two numbers A and B are such that the sum of 5% of A and 4% of B is two-third of the sum of 6% of A and 8% of B. Find the ratio of A : B.

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Question: Two numbers A and B are such that the sum of 5% of A and 4% of B is two-third of the sum of 6% of A and 8% of B. Find the ratio of A : B.
[A].

2 : 3

[B].

1 : 1

[C].

3 : 4

[D].

4 : 3

Answer: Option D

Explanation:

5% of A + 4% of B = 2  (6% of A + 8% of B)
3
5  A + 4  B = 2 6  A + 8  B
100 100 3 100 100
1  A + 1  B = 1  A + 4  B
20 25 25 75
1 – 1  A =  4 – 1  B
20 25 75 25
1  A = 1  B
100 75
A = 100 = 4 .
B 75 3

Required ratio = 4 : 3

Video Explanation: YouTube Video

What percentage of numbers from 1 to 70 have 1 or 9 in the unit’s digit?

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Question: What percentage of numbers from 1 to 70 have 1 or 9 in the unit’s digit?
[A].

1

[B].

14

[C].

20

[D].

21

Answer: Option C

Explanation:

Clearly, the numbers which have 1 or 9 in the unit’s digit, have squares that end in the digit 1. Such numbers from 1 to 70 are 1, 9, 11, 19, 21, 29, 31, 39, 41, 49, 51, 59, 61, 69.

Number of such number =14

Required percentage = 14 x 100 % = 20%.
70

Video Explanation: https://youtu.be/cBamI6iRNIA