Quantitative Aptitude - Arithmetic Ability Questions

Q:

A works twice as fast as B.If  B can complete a work in 18 days independently,the number of days  in which A and B can together finish the work is:

A) 4 days B) 6 days
C) 8 days D) 10 days
 
Answer & Explanation Answer: B) 6 days

Explanation:

Ratio of rates of working of A and B =2:1. So, ratio of times taken =1:2

Therefore, A's 1 day's work=1/9 

B's 1 day's work=1/18 

(A+B)'s 1 day's work= 1/9 + 1/18 = 1/6

so, A and B together can finish the work in 6 days

 

 

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Filed Under: Time and Work

101 33951
Q:

Two brother X and Y appeared for an exam. The probability of selection of X is 1/7 and that of B is 2/9. Find the probability that both of them are selected.

A) 1/63 B) 1/14
C) 2/63 D) 1/9
 
Answer & Explanation Answer: C) 2/63

Explanation:

Let A be the event that X is selected and B is the event that Y is selected.

P(A) = 1/7,  P(B) = 2/9.

Let C be the event that both are selected.

P(C) = P(A) × P(B) as A and B are independent events: 

       = (1/7) × (2/9)  = 2/63

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Filed Under: Probability

30 33788
Q:

In the following question, select the odd letter/letters from the given alternatives.

 

A) BFJN   B) GKOS  
C)  LPQV   D) MQU
 
Answer & Explanation Answer: C)  LPQV  

Explanation:
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Filed Under: Odd Man Out
Exam Prep: Bank Exams

0 33693
Q:

In a History examination, the average for the entire class was 80 marks. If 10% of the students scored 35 marks and 20% scored 90 marks, what was the average marks of the remaining students of the class ?

A) 25 B) 50
C) 75 D) 100
 
Answer & Explanation Answer: C) 75

Explanation:

Let the number of students in the class be 100 and let this required average be x.

Then, (10 * 95) + (20 * 90) + (70 * x) = (100 * 80)

=> 70x = 8000 - (950 + 1800) = 5250

=> x = 75.

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Filed Under: Percentage

113 33690
Q:

Calculate the area (in sq.cm) of a circle whose diameter is 35 cm.

 

A) 1925 B) 962.5
C) 857.5 D) 1715
 
Answer & Explanation Answer: B) 962.5

Explanation:
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Filed Under: Area
Exam Prep: Bank Exams

0 33603
Q:

The ratio of petrol and kerosene in the container is 3:2 when 10 liters of the mixture is taken out and is replaced by the kerosene, the ratio become 2:3. Then total quantity of the mixture in the container is:

A) 25 B) 30
C) 45 D) cannot be determined
 
Answer & Explanation Answer: B) 30

Explanation:

pool : kerosene 

   3  :  2(initially) 

   2  :  3(after replacement)

 

 Remaining QuantityInitial Quantity=1-Replaced QuantityTotal Quantity

 

(for petrol)   23=1-10k

 => K = 30

 Therefore the total quantity of the mixture in the container is 30 liters.

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Filed Under: Alligation or Mixture

83 33559
Q:

A father left a will of Rs.35 lakhs between his two daughters aged 8.5 and 16 such that they may get equal amounts when each of them reach the age of 21 years. The original amount of Rs.35 lakhs has been instructed to be invested at 10% p.a. simple interest. How much did the elder daughter get at the time of the will?

A) 17.5 lakhs B) 21 lakhs
C) 15 lakhs D) 20 lakhs
 
Answer & Explanation Answer: B) 21 lakhs

Explanation:

Let Rs.x be the amount that the elder daughter got at the time of the will. Therefore, the younger daughter got (3,500,000 - x).

 

The elder daughter’s money earns interest for (21 - 16) = 5 years @ 10% p.a simple interest.

 

The younger daughter’s money earns interest for (21 - 8.5) = 12.5 years @ 10% p.a simple interest.

 

As the sum of money that each of the daughters get when they are 21 is the same,

 

 x+5*10*x100=3,500,000-x+12.5*10*3,500,000-x100

 

 x+50x=3,500,000-x+125100*3,500,000-125x100

 

 2x+50x100+125x100=3,500,000*1+54

 

 200x+50x+125x100=94*3,500,000

 

 =>x=2,100,000=21 lakhs

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Filed Under: Simple Interest
Exam Prep: GRE

57 33538
Q:

What is the probability of getting 53 Mondays in a leap year?

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

Explanation:

1 year = 365 days . A leap year has 366 days

A year has 52 weeks. Hence there will be 52 Sundays for sure.

52 weeks = 52 x 7 = 364days

366 – 364 = 2 days

In a leap year there will be 52 Sundays and 2 days will be left.

These 2 days can be:

1. Sunday, Monday

2. Monday, Tuesday

3. Tuesday, Wednesday

4. Wednesday, Thursday

5. Thursday, Friday

6. Friday, Saturday

7. Saturday, Sunday

Of these total 7 outcomes, the favourable outcomes are 2.

Hence the probability of getting 53 days = 2/7

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Filed Under: Probability

148 33505