Aptitude and Reasoning Questions

Q:

If each edge of a cube is increased by 50%, find the percentage increase in Its surface area

A) 125% B) 150%
C) 175% D) 110%
 
Answer & Explanation Answer: A) 125%

Explanation:

Let the edge = a cm   

So increase by 50 % = a + a/2 = 3a/2  

Total surface Area of original cube = 6a2  

TSA of new cube = 63a22 =69a24=  13.5a2   

Increase in area = 13.5a2-6a2 =7.5a2  

 7.5a2 Increase % =7.5a26a2×100 = 125%

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343 64028
Q:

A problem is given to three students whose chances of solving it are 1/2, 1/3 and 1/4 respectively. What is the probability that the problem will be solved?

A) 1/4 B) 1/2
C) 3/4 D) 7/12
 
Answer & Explanation Answer: C) 3/4

Explanation:

Let A, B, C be the respective events of solving the problem and A , B, C be the respective events of not solving the problem. Then A, B, C are independent event

A, B, C are independent events

Now,  P(A) = 1/2 , P(B) = 1/3 and P(C)=1/4

 PA=12, PB=23, PC= 34

 P( none  solves the problem) = P(not A) and (not B) and (not C)  

                  = PABC 

                  = PAPBPC          A, B, C are Independent                       

                  =  12×23×34  

                  = 14  

Hence, P(the problem will be solved) = 1 - P(none solves the problem) 

                = 1-14= 3/4

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214 63789
Q:

Fresh fruit contains 68% water and dry fruit contains 20% water. How much dry fruit can be obtained from 100 kg of fresh fruits ?

A) 20 B) 30
C) 40 D) 50
 
Answer & Explanation Answer: C) 40

Explanation:

The fruit content in both the fresh fruit and dry fruit is the same.

 

Given, fresh fruit has 68% water.so remaining 32% is fruit content. weight of fresh fruits is 100kg

 

Dry fruit has 20% water.so remaining 80% is fruit content.let weight if dry fruit be y kg.

 

Fruit % in freshfruit = Fruit% in dryfruit 

 

Therefore, (32/100) x 100 = (80/100 ) x y 

 

we get, y = 40 kg.

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515 63166
Q:

Tea worth of Rs. 135/kg & Rs. 126/kg are mixed with a third variety in the ratio 1: 1 : 2. If the mixture is worth Rs. 153 per kg, the price of the third variety per kg will be____?

A) Rs. 169.50 B) Rs.1700
C) Rs. 175.50 D) Rs. 180
 
Answer & Explanation Answer: C) Rs. 175.50

Explanation:

Since first second varieties are mixed in equal proportions, so their average price = Rs.(126+135)/2= Rs.130.50

So, Now the mixture is formed by mixing two varieties, one at Rs. 130.50 per kg and the other at say Rs. 'x' per kg in the ratio 2 : 2, i.e., 1 : 1. We have to find 'x'.

 

Cost of 1 kg tea of 1st kind         Cost of 1 kg tea of 2nd kind 

 

 

  

x-153/22.50 = 1  => x - 153 = 22.50  => x=175.50.

 Hence, price of the third variety = Rs.175.50 per kg.

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279 55537
Q:

The value of a machine depreciates at the rate of 10% every year. It was purchased 3 years ago. If its present value is Rs. 8748, its purchase price was :

A) 10000 B) 12000
C) 14000 D) 16000
 
Answer & Explanation Answer: B) 12000

Explanation:

Purchase price = Rs.87481-101003 = Rs. [8748 * 10/9 * 10/9 * 10/9] = Rs.12000

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302 55455
Q:

In an examination, a student scores 4 marks for every correct answer and loses 1 mark for every wrong answer. If he attempts all 60 questions and secures 130 marks, the no of questions he attempts correctly is :

A) 35 B) 38
C) 40 D) 42
 
Answer & Explanation Answer: B) 38

Explanation:

Let the number of correct answers be X.

Number of incorrect answers = (60 – X).

4x – (60 – x) = 130

=> 5x = 190 

=> x = 38

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149 55252
Q:

A student has to obtain 33% of the total marks to pass. He got 125 marks and failed by 40 marks. The maximum marks are :

A) 500 B) 600
C) 800 D) 1000
 
Answer & Explanation Answer: A) 500

Explanation:

Given that the student got 125 marks and still he failed by 40 marks

 

=> The minimum pass mark = 125 + 40 = 165

 

Given that minimum pass mark = 33% of the total mark

 

=> total mark =33/100 =165

 

=> total mark = 16500/33 = 500

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202 54656
Q:

A is B's sister. C is B's mother. D is C's father. E is D's mother. Then, how is A related to D?

A) Grandfather B) Grandmother
C) Daughter D) Granddaughter
 
Answer & Explanation Answer: D) Granddaughter

Explanation:

A is the sister of B and B is the daughter of C.

So, A is the daughter of C. Also, D is the father of C.

So, A is the granddaughter of D. 

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