Aptitude and Reasoning Questions

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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243 70636
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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351 66372
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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558 65150
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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328 58551
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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1767 58388
Q:

A and B invest in a business in the ratio 3 : 2. If 5% of the total profit goes to charity and A's share is Rs. 855, the total profit is :

A) 500 B) 1000
C) 1500 D) 2000
 
Answer & Explanation Answer: C) 1500

Explanation:

Let the total profit be Rs. 100.

 

 

 

After paying to charity, A's share  = (95*3/5) = Rs. 57.

 

 

 

If A's share is Rs. 57, total profit = Rs. 100.

 

 

 

If A's share is Rs. 855, total profit  = (100/57*855) = 1500.

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137 58020
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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155 57459
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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213 56797