Quantitative Aptitude - Arithmetic Ability Questions

Q:

Relation Between Efficiency and Time

A is twice as good a workman as B and is therefore able to finish a piece of work in 30 days less than B.In how many days they can complee the whole work; working together?

Answer

Ratio of times taken by A and B = 1 : 2.


The time difference is (2 - 1) 1 day while B take 2 days and A takes 1 day.


If difference of time is 1 day, B takes 2 days.


If difference of time is 30 days, B takes 2 x 30 = 60 days.


So, A takes 30 days to do the work.


 


A's 1 day's work = 1/30


B's 1 day's work = 1/60


(A + B)'s 1 day's work = 1/30 + 1/60 = 1/20


A and B together can do the work in 20 days.

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Subject: Time and Work

253 64821
Q:

Find the factors of (x2 - x - 132)?

 

A) x - 11x - 12 B) (x + 12)(x - 11)
C) (x + 11)(x + 12) D) (x - 12)(x + 11)
 
Answer & Explanation Answer: D) (x - 12)(x + 11)

Explanation:
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Filed Under: Simplification
Exam Prep: Bank Exams

10 64598
Q:

Find at what time between 8 and 9 o'clock will the hands of a clock be in the same straight line but not together ?

A) 100/11 min past 8 B) 120/11 min past 8
C) 90/11 min past 8 D) 80/11 min past 8
 
Answer & Explanation Answer: B) 120/11 min past 8

Explanation:

In this type of problems the formulae is 5x-30×1211
x is replaced by the first interval of given time Here i.e 8
5*8-30*1211
12011min

Therefore the hands will be in the same straight line but not
together at 12011 min.past 8.

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Filed Under: Clocks
Exam Prep: Bank Exams
Job Role: Bank PO

102 64562
Q:

A mixture contains alcohol and water in the ratio 4 : 3. If 5 liters of water is added to the mixture, the ratio becomes 4: 5. Find the quantity of alcohol in the given mixture.

A) 10 B) 12
C) 15 D) 18
 
Answer & Explanation Answer: A) 10

Explanation:

Let the quantity of alcohol and water be 4x litres and 3x litres respectively

 

4x/(3x+5) = 4/5 

 

20x = 4(3x+5)

 

8x = 20

 

x = 2.5

 

Quantity of alcohol = (4 x 2.5) litres = 10 litres.

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Filed Under: Ratios and Proportions

341 64536
Q:

405 sweets were distributed equally among children in such a way that the number of sweets received by each child is 20% of the total number of children. How many sweets did each child recieve ?

A) 9 B) 10
C) 11 D) 12
 
Answer & Explanation Answer: A) 9

Explanation:

Let the total number of children be x. 

Then, x * (20% of x) = 405  

=> x * 20x/100 = 405 

15x2 = 405 

 

=> x=45 

 

Number of sweets received by each child = 20% of 45 = 9.

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Filed Under: Percentage

294 64487
Q:

What should come in place of question mark (?) in the following number series?

38, 195, ?, 4905, 24530, 122655

A) 980 B) 885
C) 824 D) 1021
 
Answer & Explanation Answer: A) 980

Explanation:

The given series follows the pattern that,

 

×5+5,   ×5+5,   ×5+5,   ×5+5,   ×5+5

 

38 x 5 + 5  = 195

 

195 x 5 + 5 = 980

 

980 x 5 + 5 = 4905

 

4905 x 5 + 5 = 24530

 

24530 x 5 + 5 = 122655

 

So the missing number is 980 .

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Filed Under: Odd Man Out
Exam Prep: GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

7 64358
Q:

If 75% of a number is added to 75, then the result is the number itself. The number is :

A) 100 B) 200
C) 300 D) 400
 
Answer & Explanation Answer: C) 300

Explanation:

Let the number be x, Then 

75% of x + 75 = x 

=> x - 75x/100 =75 

=> x =  300 .

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Filed Under: Percentage

264 64343
Q:

An accurate clock shows 8 o'clock in the morning. Through how may degrees will the hour hand rotate when the clock shows 2 o'clock in the afternoon?

A) 360 B) 180
C) 90 D) 60
 
Answer & Explanation Answer: B) 180

Explanation:

Angle traced by the hour hand in 6 hours=(360/12)*6

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Filed Under: Clocks
Exam Prep: Bank Exams
Job Role: Bank PO

190 64286