23
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:

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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2 95
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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1 118
Q:

When 5% is lost in grinding Maize, a country has to import 20 million bags; but when only 2% is lost, it has to import only 15 million bags. Find the quantity of Maize, which grows in the country ?

A) 188 million B) 166 2/3 million
C) 192 3/4 million D) None
 
Answer & Explanation Answer: B) 166 2/3 million

Explanation:

5% - 2% = 3%
=> 3% ------ 5 million bags
100% ---- ?
=> 166 2/3 million bags.

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2 155
Q:

If x = √8 - √7, y = √6 - √5 and z = √10 - 3, which of the following is true  ?

A) x > y < z B) x < y < z
C) x > y > z D) z < x < y
 
Answer & Explanation Answer: D) z < x < y

Explanation:

x = √8 - √7 = 1/(√8 + √7) and y = √6 - √5 = 1/(√6 + √5) and z = √10 - 3 = 1/(√10 + 3)

As (√8 + √7) > (√6 + √5), (√8 - √7) < (√6 - √5)

As (√10 + 3) > (√8 + √7) > (√6 + √5)

z < x < y.

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1 126
Q:

Difference between two numbers is 5, six times of the smaller lacks by 6 from the four times of the greater. Find the numbers ?

A) 12 & 7 B) 13 & 8
C) 15 & 10 D) 14 & 9
 
Answer & Explanation Answer: A) 12 & 7

Explanation:

x – y = 5

4x – 6y = 6

x = 12 y = 7

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2 154