Verbal Reasoning - Mental Ability Questions

Q:

There are 6561 balls are there out of them 1 is heavy. Find the minimum number of times the balls have to be weighted for finding out the heavy ball ?

A) 2414 B) 204
C) 87 D) 8
 
Answer & Explanation Answer: D) 8

Explanation:

Suppose there are 9 balls

 

Let us give name to each ball B1 B2 B3 B4 B5 B6 B7 B8 B9

 

Now we will divide all the balls into 3 groups.

 

Group1 - B1 B2 B3

 

Group2 - B4 B5 B6

 

Group3 - B7 B8 B9

 

Step1 - Now weigh any two groups. Let's assume we choose Group1 on left side of the scale and Group2 on the right side.

 

So now when we weigh these two groups we can get 3 outcomes.

 

Weighing scale tilts on left - Group1 has a heavy ball.
Weighing scale tilts on right - Group2 has a heavy ball.
Weighing scale remains balanced - Group3 has a heavy ball.
Lets assume we got the outcome as 3. i.e Group 3 has a heavy ball.

 

Step2 - Now weigh any two balls from Group3. Lets assume we keep B7 on left side of the scale and B8 on right side.

 

So now when we weigh these two balls we can get 3 outcomes.

 

Weighing scale tilts on left - B7 is the heavy ball.
Weighing scale tilts on right - B8 is the heavy ball.
Weighing scale remains balanced - B9 is the heavy ball.
The conclusion we get from this Problem is that each time weigh. We element 2/3 of the balls.

 

As we came to conclusion that Group3 has the heavy ball from Step1, we remove 6 balls from the equation i.e (2/3) of 9.

 

Simillarly we do the ame thing for the Step2.

 

Now going with this conclusion. We have 6561 balls.

 

Step - 1

 

Divided into 3 groups

 

Group1 - 2187Balls

 

Group2 - 2187Balls

 

Group3 - 2187Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 2

 

Divided into 3 groups

 

Group1 - 729Balls

 

Group2 - 729Balls

 

Group3 - 729Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 3

 

Divided into 3 groups

 

Group1 - 243Balls

 

Group2 - 243Balls

 

Group3 - 243Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 4

 

Divided into 3 groups

 

Group1 - 81Balls

 

Group2 - 81Balls

 

Group3 - 81Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 5

 

Divided into 3 groups

 

Group1 - 27Balls

 

Group2 - 27Balls

 

Group3 - 27Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 6

 

Divided into 3 groups

 

Group1 - 9Balls

 

Group2 - 9Balls

 

Group3 - 9Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 7

 

Divided into 3 groups

 

Group1 - 3Balls

 

Group2 - 3Balls

 

Group3 - 3Balls

 

Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball.

 

Step - 8

 

So now when we weigh 2 balls out of 3 we can get 3 outcomes.

 

Weighing scale tilts on left - left side placed is the heavy ball.
Weighing scale tilts on right - right side placed is the heavy ball.
Weighing scale remains balanced - remaining ball is the heavy ball.
So the general answer to this question is, it is always multiple of 3 steps.

 

For 9 balls  32= 9. therefore 2 steps

 

For 6561 balls 38 = 6561 therefore 8 steps

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Filed Under: Arithmetical Reasoning
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Q:

Nandini is the only daughter of Madan's sister Sangita's brother. How is Nandini related to Madam?

A) Daughter B) Niece
C) Cousin D) Niece or Daughter
 
Answer & Explanation Answer: D) Niece or Daughter

Explanation:
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Filed Under: Blood Relations
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53 14305
Q:

Directions : For the Assertion (A) and Reason (R) below, choose the correct alternative 

Assertion (A)  :   Red colour of blood is due to haemoglobin. 

Reason (R)     :  Haemoglobin is a red pigment. 

A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is NOT the correct explanation of A.
C) A is true but R is false. D) A is false but R is true.
 
Answer & Explanation Answer: A) Both A and R are true and R is the correct explanation of A.

Explanation:

Haemoglobin is the blood pigment that imparts red colour to the blood. 

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Filed Under: Assertion and Reason

3 14290
Q:

Pointing to the lady on the platform. Manju said "She is the sister of the father of my mother's son". How is  the lady related to Manju ?

A) Mother B) Sister
C) Aunt D) Niece
 
Answer & Explanation Answer: C) Aunt

Explanation:

Manju's mother's son----> Manju's brother.

Manju's brother's father ----> Munju's father;

Father's sister Manju's aunt. 

 

 

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Filed Under: Blood Relations

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Q:

A, B, C, D and E are sitting in a row. B is between A and K Who among them is in the middle ? 

I. A is left of 13 and right of D. 

II.C is at the right end. 

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 in both the statements together are needed.
 
Answer & Explanation Answer: D) If the data in both the statements together are needed.

Explanation:

Clearly, we have the order : A. a E. From I, we have the order : D, A, B. E.

From II, we get the complete sequence as D, A, B. E, C.

Clearly. B is in the middle. So, both I and II are required. 

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Filed Under: Data Sufficiency

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Q:

Identify the diagram that best represents the relationship among the given classes.

 

Women, Trainer, Pilot

A) 1 B) 2
C) 3 D) 4
 
Answer & Explanation Answer: A) 1

Explanation:
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Filed Under: Logical Venn Diagram
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Q:

The following equation is incorrect. Which two signs should be interchanged to correct the equation?

10 x 4 + 5 - 30 ÷ 6 = 31

A) x and - B) ÷ and -
C) + and ÷ D) - and +
 
Answer & Explanation Answer: A) x and -

Explanation:
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Filed Under: Mathematical Operations
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Q:

Iam facing south. I turn right and walk 20 m. Then I turn right again and walk 10m. Then I turn left and walk 10m and then turning right walk 20m. Then I turn right again and walk 60m. In which direction am I from the starting point?

A) North B) North-West
C) North-East D) East
 
Answer & Explanation Answer: C) North-East

Explanation:

The movements of the person are from A to F, as shown in Fig. Clearly, the final position is F which is to the North-east of the starting point A

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Filed Under: Direction Sense Test

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