Searching for "number"

Q:

The average age of a group of persons going for picnic is 16 years. Twenty new persons with an average age of 15 years join the group on the spot due to which their average age becomes 15.5 years. The number of persons initially going for picnic is :

A) 15 B) 20
C) 23 D) 24
 
Answer & Explanation Answer: B) 20

Explanation:

Let the initial number of persons be x. Then,

16x + 20 * 15 = 15.5 (x + 20) <=> 0.5x = 10 <=> x = 20.

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Q:

The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero ?

A) 0 B) -1
C) 1 D) none of these
 
Answer & Explanation Answer: A) 0

Explanation:

Average of 20 numbers = 0. 

 

Sum of 20 numbers = (0 * 20) = 0. 

 

It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (- a).

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Filed Under: Average

Q:

The average of six numbers is 3.95. The average of two of them is 3.4, while the average of the other two is 3.85. What is the average of the remaining two numbers ?

A) 3.6 B) 4.6
C) 6.5 D) 7.3
 
Answer & Explanation Answer: B) 4.6

Explanation:

 Sum of the remaining two numbers = (3.95 * 6) - [(3.4 * 2) + (3.85 * 2)]

                                                   = 23.70 - (6.8 + 7.7) = 23.70 - 14.5 = 9.20.

Required average = (9.2 / 2) =  4.6.

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Q:

Of the four numbers, whose average is 60, the first is one-fourth of the sum of the last three. The first number is :

A) 17 B) 29
C) 36 D) 48
 
Answer & Explanation Answer: D) 48

Explanation:

Let the first number be x,

Then, sum of the four numbers = x + 4x = 5x.

so,  5x/4 = 60 or x = (60 * 4) / 5 = 48.

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Q:

The average of five numbers is 27. If one number is excluded, the average becomes 25. The excluded number is :

A) 25 B) 35
C) 45 D) 55
 
Answer & Explanation Answer: B) 35

Explanation:

Excluded number = (27 x 5)  -  (25 x 4) = 135 - 100 = 35.

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Q:

The average of 7 consecutive numbers is 20. The largest of these numbers is :

A) 21 B) 22
C) 23 D) 24
 
Answer & Explanation Answer: C) 23

Explanation:

Let the numbers be x, x + 1, x + 2,  x + 3, x + 4, x + 5 and x + 6,

Then   (x + (x + 1) + (x + 2) + (x + 3) + (x + 4) + (x + 5) + (x + 6)) / 7 = 20.

or  7x + 21 = 140 or 7x = 119 or x =17.

Latest number = x + 6 = 23.

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Q:

In a certain code language, '297' means 'tie clip button'. Which number means 'button' ? 

I. In that language '926' means 'clip your tie'. 

II. In that language '175' means 'hole and button'. 

A) If the data in statement I alone are sufficient to answer the question B) If the data in statement II alone are sufficient answer the question
C) If the data either in I or II alone are sufficient to answer the question; D) If the data even in both the statements together are not sufficient to answer the question
 
Answer & Explanation Answer: C) If the data either in I or II alone are sufficient to answer the question;

Explanation:

Comparing the information in the question with statement 1. we find that '2' and '9' are the codes for 'tie' and 'dip'. So, '7' represents 'button'.

Thus, I alone iS sufficient.

Again, comparing the information in the question with II, WO find that the common code number '7' stands for the common word 'button'.

Thus, II alone also is sufficient. 

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Filed Under: Data Sufficiency

Q:

How many new year's greeting cards were sold this year in your shop ? 

I. Last year 2935 cards were sold. 

II. The number of cards sold this year was 1.2 times that of last year

A) If the data in statement I alone are sufficient to answer the question i B) If the data in statement II alone are sufficient answer the question
C) If the data either in I or II alone are sufficient to answer the question; D) If the data in both the statements together are needed.
 
Answer & Explanation Answer: D) If the data in both the statements together are needed.

Explanation:

From both the given statements, we find that the number of cards sold this year (2935 x 1.2) = 3522.

S0. both I and II together are required. 

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Filed Under: Data Sufficiency