24
Q:

In a class of 60 students, the number of boys and girls participating in the annual sports is in the ratio 3 : 2 respectively. The number of girls not participating in the sports is 5 more than the number of boys not participating in the sports. If the number of boys participating in the sports is 15, then how many girls are there in the class ?

A) 20 B) 25
C) 30 D) Data inadequate

Answer:   C) 30



Explanation:

Let the number of boys and girls participating in sports be 3x and 2x respectively.

Then, 3x = 15 or x = 5.

So, number of girls participating in sports = 2x = 10.

Number of students not participating in sports = 60 - (15 + 10) = 35.

Let number of boys not participating in sports be y.

Then, number of girls not participating in sports = (35 -y).

Therefore (35 - y) = y + 5 {\color{Blue} \Leftrightarrow } 2y {\color{Blue} \Leftrightarrow } 30 {\color{Blue} \Leftrightarrow } y = 15.

So, number of girls not participating in sports = (35 - 15) = 20.

Hence, total number of girls in the class = (10 + 20) = 30.

Q:

In a parking lot there are two types of vehicles, two wheelers and four wheelers. The total number of the vehicles in the parking lot is 200. When the number of the wheels of all the vehicles is counted it is counted to be 580. Find the total number of the four wheeler vehicles in the parking lot ?

A) 110 B) 90
C) 100 D) 180
 
Answer & Explanation Answer: B) 90

Explanation:

Let number of 2 wheelers be 'x'
and 4 wheelers be 'y'

Given total number of vehicles = 200
i.e, x + y = 200 ....(1)

Given total number of wheels = 580
i.e, 2x + 4y = 580 ...(2)

By solving (1)&(2), we get

y = 90
=> x = 110

Therefore, number of two wheelers = 110
number of four wheelers = 90

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8 135
Q:

Rajitha has a calculator, which has 10 digits. She want to clean the calculator by removing all the keys and while reassembling it, she interchanged the locations of 3 pairs of keys. For example, if she placed the key ‘3’ in the place of the key ‘7’, she placed the key ‘7’ only in the place of the key ‘3’ and not any other key. All keys that were interchanged corresponded only to numbers. Later, she input some calculations and obtained outputs as provided in the table below. The input is shown in terms of the keys that Kavitapressed, while the output is the output displayed by the calculator.

Output:

1.   95 + 84=128
2.   128 + 64=195
3.   912 + 43=942
4.   178 + 19=192

Question :

Which of the following pair of digits is unchanged ?

A) 9, 0, 3 B) 1, 3, 8
C) 7, 0, 1 D) 2, 4, 1
 
Answer & Explanation Answer: C) 7, 0, 1

Explanation:
0 1 2 3 4 5 6 7 8 9
0 1 4 8 2 6 5 7 3 9

Here pairs interchanged are

2, 4 

3, 8

5, 6

Unchanged are 0, 1, 7, 9

 

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4 232
Q:

 What is the difference between the local values of 3 in the number 43403 ?

A) 0 B) 3030
C) 3003 D) 2997
 
Answer & Explanation Answer: D) 2997

Explanation:

3000 – 3 = 2997

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6 281
Q:

Find the least number by which 175760 be divided to make it a perfect cube.

A) 6 B) 10
C) 9 D) 30
 
Answer & Explanation Answer: B) 10

Explanation:

175760 =2³ x 2 x 5 x 13³
= 2³ x 2 x 5 x 13³

To make perfect cube, it must be divided by 2 x 5 = 10

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3 364
Q:

The sum of three consecutive multiples of 3 is 72. What is the second largest number ?

A) 27 B) 24
C) 21 D) 42
 
Answer & Explanation Answer: B) 24

Explanation:

Let the numbers be 3x, 3x + 3 and 3x + 6.
Then,
3x + (3x + 3) + (3x + 6) = 72
9x = 63
x = 7
Largest number = 3x + 6 = 27.

=> Second largest number = 27 - 3 = 24

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