Quantitative Aptitude - Arithmetic Ability Questions

Q:

In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, the present age of B is :

A) 19 B) 29
C) 39 D) 49
 
Answer & Explanation Answer: C) 39

Explanation:

Let B's present age = x years. Then, A's present age = (x + 9) years.
(x + 9) + 10 = 2(x - 10)

 => x + 19 = 2x - 20

 => x =39.

Report Error

View Answer Report Error Discuss

Filed Under: Problems on Ages

346 68366
Q:

A person crosses a 600 m long street in 5 minutes, What is his speed in km per hour?

A) 3.6 B) 7.2
C) 8.4 D) 10
 
Answer & Explanation Answer: B) 7.2

Explanation:

Speed =   6005×60 m/sec= 2 m/sec = 2 x (18/5) km/hr = 7.2 km/hr

Report Error

View Answer Report Error Discuss

Filed Under: Time and Distance

314 68285
Q:

The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is:

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

Explanation:

Let the numbers 13a and 13b.

Then, 13a x 13b = 2028

=>ab = 12.

Now, the co-primes with product 12 are (1, 12) and (3, 4).

[Note: Two integers a and b are said to be coprime or relatively prime if they have no common positive factor other than 1 or, equivalently, if their greatest common divisor is 1 ]

So, the required numbers are (13 x 1, 13 x 12) and (13 x 3, 13 x 4).

Clearly, there are 2 such pairs.

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM

231 68160
Q:

An air conditioner can cool the hall in 40 miutes while another takes 45 minutes to cool under similar conditions. If both air conditioners are switched on at same instance then how long will it take to cool the room approximately ?

A) 18 minutes B) 19 minutes
C) 22 minutes D) 24 minutes
 
Answer & Explanation Answer: C) 22 minutes

Explanation:

Let the two conditioners be A and B

 

'A' cools at 40min

 

'B' at 45min

 

Together = (a x b)/(a + b)

= (45 x 40)/(45 + 40)

= 45 x 40/85

= 21.1764

= 22 min (approx).

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: GRE , GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

92 67706
Q:

1397 x 1397 = ?

Here what replaces '?' 

A) 1951609 B) 1821504
C) 2031489 D) 1847879
 
Answer & Explanation Answer: A) 1951609

Explanation:

1397 x 1397

Number System mcq solution image

Report Error

View Answer Report Error Discuss

Filed Under: Simplification
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

17 67680
Q:

A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is :

A) 9.5 km/hr B) 10 km/hr
C) 10.5 km/hr D) 11 km/hr
 
Answer & Explanation Answer: B) 10 km/hr

Explanation:

Man's rate in still water = (15 - 2.5) km/hr = 12.5 km/hr.

Therefore,  Man's rate against the current = (12.5 - 2.5) = 10 km/hr.

Report Error

View Answer Report Error Discuss

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

109 67566
Q:

A began a business with Rs. 85,000. He was joined afterwards by B with Ks. 42,500. For how much period does B join, if the profits at the end of the year are divided in the ratio of 3 : 1 ?

A) 4 months B) 5 months
C) 6 months D) 8 months
 
Answer & Explanation Answer: D) 8 months

Explanation:

Suppose B joined for x months . Then,  ( 85000 * 12 )/(42500 * x) = 3. or x = (85000 * 12) / (42500 * 3) = 8.

So, B joined for 8 months.

Report Error

View Answer Report Error Discuss

Filed Under: Partnership

97 67474
Q:

Simplify 2392-21+8-72=?2

 

A) 4 B) 5
C) 6 D) 9
 
Answer & Explanation Answer: C) 6

Explanation:

?2 = 2×78-21+8+49-148= 57 - 21=36=> ? = ±6

Report Error

View Answer Report Error Discuss

Filed Under: Simplification
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

15 67398