Quantitative Aptitude - Arithmetic Ability Questions

Q:

If the sum and diference of two numbers are 20 and 8 respectively, then the difference of their squares is :

A) 120 B) 140
C) 160 D) 180
 
Answer & Explanation Answer: C) 160

Explanation:

Let the numbers be x and y. Then, x + y = 20 and x - y = 8.

 x^2 - y^2 = (x + y) (x - y) = 20 x 8 = 160.

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Filed Under: Problems on Numbers

7 10742
Q:

A man saves Rs. 200 in each of the first three months of his service. In each of the subsequent months his saving increases by Rs. 40 more than the saving of immediately previous month. His total saving from the start of service will be Rs. 11040 after ?

A) 19 months B) 21 months
C) 18 months D) 20 months
 
Answer & Explanation Answer: B) 21 months

Explanation:

Total savings = 200 + 200 + 200 + 240 + 280 + ... to n months = 11040

= 120 + 80 + 160 + 40 + 200 + 240 + ....n terms
= 40 + 80 + 120 + 160 + 200 + 240 + ...n terms
= n/2[2a + (n-1)d] + 80 + 40 = 11040
= n/2[240 + (n-1)40] = 10920
= n[6+n-1] = 546
= n[n+5] = 546
n = 21

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

9 10731
Q:

A square and rectangle have equal areas. If their perimeters are p and q respectively. Then

A) p B) p>q
C) p=q D) none of these
 
Answer & Explanation Answer: A) p
Explanation:

square and a rectangle with equal areas will satisfy the
relation p < q

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

5 10691
Q:

Two trains are running at 60 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 6 seconds. What is the length of the fast train ?

A. 6623 mts

B. 6632 mts

C.6345 mts

D. 6354 mts

A) Option A B) Option B
C) Option C D) Option D
 
Answer & Explanation Answer: A) Option A

Explanation:

As Trains are moving in same direction,

Relative Speed = 60-20 = 40 kmph

--> 40×518=1009 m/sec

 

Length of Train= Speed * Time

 

Length = 1009×6

2003=6623 mts 

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Filed Under: Problems on Trains
Exam Prep: CAT , Bank Exams
Job Role: Bank PO , Bank Clerk

12 10671
Q:

What is the sum which earned interest?
I. The total simple interest was Rs. 7000 after 7 years.
II. The total of sum and simple interest was double of the sum after 5 years.

A) I alone sufficient while II alone not sufficient to answer B) II alone sufficient while I alone not sufficient to answer
C) Either I or II alone sufficient to answer D) Both I and II are necessary to answer
 
Answer & Explanation Answer: D) Both I and II are necessary to answer

Explanation:

Let the sum be Rs. x.

I  gives, S.I. = Rs. 7000 and T = 7 years.

II gives, Sum + S.I. for 5 years = 2 x Sum Sum = S.I. for 5 years.

Now, S.I. for 7 years = Rs. 7000.

therefore, S.I. for 1 year =  Rs. 1000.

Thus, I and II both are needed to get the answer.

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Filed Under: Simple Interest
Exam Prep: GRE
Job Role: Bank PO

3 10660
Q:

 On what dates of April, 2001 did Wednesday fall ?

A) 1st, 8th, 15th, 22nd, 29th B) 2nd, 9th, 16th, 23rd, 30th
C) 3rd, 10th, 17th, 24th D) 4th, 11th, 18th, 25th
 
Answer & Explanation Answer: D) 4th, 11th, 18th, 25th

Explanation:

ke

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Filed Under: Calendar

10 10653
Q:

A vertical toy 18 cm long casts a shadow 8 cm long on the ground. At the same time a pole casts a shadow 48 m. long on the ground. Then find the height of the pole ?

A) 1080 cm B) 180 m
C) 108 m D) 118 cm
 
Answer & Explanation Answer: C) 108 m

Explanation:

We know the rule that,

 

At particular time for all object , ratio of height and shadow are same.

 

Let the height of the pole be 'H'

 

Then

 188=H48

 

=> H = 108 m.

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Filed Under: Height and Distance
Exam Prep: CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

19 10651
Q:

Jack takes 20 minutes to jog around the race course one time, and 25 minutes to jog around a second time. What is his average speed in miles per hour for the whole jog if the course is 3 miles long?

A) 6 B) 8
C) 9 D) 10
 
Answer & Explanation Answer: B) 8

Explanation:

Average speed = total distance / total time

Total distance covered = 6 miles; total time = 45 minutes = 0.75 hours

Average speed = 6/ 0.75 = 8 miles/hour

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Filed Under: Height and Distance
Exam Prep: GRE

23 10646