Quantitative Aptitude - Arithmetic Ability Questions

Q:

The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then :

A) x = y + z B) 2x = y + z
C) 3x = 2y - 2z D) none of these
 
Answer & Explanation Answer: B) 2x = y + z

Explanation:

Clearly, we  have : x = (3y + 3z ) / 6 or 2x = y + z.

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Filed Under: Average

13 14058
Q:

How many arrangements of the letters of the word ‘BENGALI’ can be made if the vowels are never together.

A) 120 B) 640
C) 720 D) 540
 
Answer & Explanation Answer: C) 720

Explanation:

There are 7 letters in the word ‘Bengali of these 3 are vowels and 4 consonants.

 

Considering vowels a, e, i as one letter, we can arrange 4+1 letters in 5! ways in each of which vowels are together. These 3 vowels can be arranged among themselves in 3! ways.

 

Total number of words = 5! x 3!= 120 x 6 = 720

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6 14057
Q:

6 boys and 8 girls can do job in 10 days , 26 boys & 48 women do work in 2 days. Find time taken by 15 boys and 20 girls to do same work ?

A) 2 days B) 3 days
C) 4 days D) 5 days
 
Answer & Explanation Answer: C) 4 days

Explanation:

One day work of 6 boys and 8 girls is given as 6b + 8g = 1/10 -------->(I)

 


One day work of 26 boys and 48 women is given as 26b + 48w = 1/2 -------->(II)

 

Divide both sides by 2 in (I) and then multiply both sides by 5

Now we get, 15b + 20g = 1/4.

Therefore, 15 boys and 20 girls can do the same work in 4 days.

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Filed Under: Time and Work
Exam Prep: GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk , Analyst

14 14011
Q:

What should come in place of x in the following equation?

 x128 = 162x

A) 13 B) 12
C) 17 D) 16
 
Answer & Explanation Answer: B) 12

Explanation:

x128 = 162x

 

Then x2 = 162x128

  

   = Sqrt of 82 x 62 x 32

 

   = 8 x 6 x 3

 

   x2  = 144.

 

 x  = 12.

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Filed Under: Square Roots and Cube Roots
Exam Prep: GATE , CAT , Bank Exams , AIEEE
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8 14010
Q:

A piece of ribbon 4 yards long is used to make bows requiring 15 inches of ribbon for each. What is the maximum number of bows that can be made?

A) 8 B) 9
C) 10 D) 11
 
Answer & Explanation Answer: B) 9

Explanation:

The maximum number of bows will be 4 yards (= 4 x 36 inches) divided by 15 inches.

This gives 9.6. But as a fraction of a bow is no use, we can only make 9 bows.

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Filed Under: Numbers
Exam Prep: GRE

22 13979
Q:

Pipe A can fill a tank in 16 minutes and pipe B cam empty it in 24 minutes. If both the pipes are opened together after how many minutes should pipe B be closed, so that the tank is filled in 30 minutes  ?

A) 21 min B) 24 min
C) 20 min D) 22 min
 
Answer & Explanation Answer: A) 21 min

Explanation:

Let the pipe B be closed after 'K' minutes.

30/16 - K/24 = 1 => K/24 = 30/16 - 1 = 14/16

=> K = 14/16 x 24 = 21 min.

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Filed Under: Pipes and Cistern
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

19 13966
Q:

A drink vendor has 80 liters of Mazza, 144 liters of Pepsi, and 368 liters of Sprite. He wants to pack them in cans, so that each can contains the same number of liters of a drink, and doesn't want to mix any two drinks in a can. What is the least number of cans required?

A) 35 B) 36
C) 37 D) 38
 
Answer & Explanation Answer: C) 37

Explanation:

If we want to pack the drinks in the least number of cans possible, then each can should contain the maximum numbers of liters possible.As each can contains the same number liters of a drink, the number of liters in each can is a comman factor for 80,144 and 368; and it is also the highest such factor, as we need to store the maximum number of liters in each can.

So, the number of liters in each can  = HCF of 80,144 and 368 = 16 liters.

Now, number of cans of Maaza = 80/16 = 5

Number of cans of Pepsi = 144/16 = 9

Number of cans of Sprite = 368/16 = 23

Thus, the total number of cans required = 5 + 9 + 23 = 37 

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Filed Under: HCF and LCM

24 13951
Q:

If V = 12R / (r + R) , then R =

A) Vr / (12 - V) B) Vr + (V /12 )
C) V D) V / (r - 12 )
 
Answer & Explanation Answer: A) Vr / (12 - V)

Explanation:

We have to rearrange the equation to make R the subject.

Start by cross multiplying by (r + R); V (r + R) = 12R

Multiply out the bracket Vr + VR = 12R

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Filed Under: Numbers
Exam Prep: GRE

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