6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

Consider the word ROTOR. Whichever way you read it, from left to right or from right to left, you get the same word. Such a word is known as palindrome. Find the maximum possible number of 5-letter palindromes.

A) 17756	B) 17576
C) 12657	D) 12666

Answer & Explanation Answer: B) 17576

Explanation:

The first letter from the right can be chosen in 26 ways because there are 26 alphabets.

Having chosen this, the second letter can be chosen in 26 ways

The first two letters can chosen in 26 x 26 = 676 ways

Having chosen the first two letters, the third letter can be chosen in 26 ways.

All the three letters can be chosen in 676 x 26 =17576 ways.

It implies that the maximum possible number of five letter palindromes is 17576 because the fourth letter is the same as the second letter and the fifth letter is the same as the first letter.

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Filed Under: Permutations and Combinations

13 16093

Q:

What is the total surface area of a right circular cone of height 14 cm and base radius 7 cm?

A) 344.35 sq.cm	B) 462 sq.cm
C) 498.35 sq.cm	D) None of these

Answer & Explanation Answer: C) 498.35 sq.cm

Explanation:

h = 14 cm, r = 7 cm.

So, l = $[\sqrt{7^{2} + 14^{2}}] = \sqrt{245} = 7 \sqrt{5} c m$

Total surface area = $πrl + {πr}^{2}$ = $\frac{22}{7} \times 7 \times 7 \sqrt{5} + \frac{22}{7} \times 7 \times 7$

= $154 (\sqrt{5} + 1)$

= (3.236 x 154) sq.cm

= 498.35 sq.cm

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Filed Under: Volume and Surface Area

6 16078

Q:

The banker's discount of a certain sum of money is Rs. 72 and the true discount on the

same sum for the same time is Rs. 60. The sum due is:

A) 290	B) 480
C) 360	D) 420

Answer & Explanation Answer: C) 360

Explanation:

Sum =(B.D. x T.D.)/(B.D. - T.D.)

= Rs. (72 x 60) / (72 - 60)

= Rs. (72 x 60) /12

= Rs. 360.

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Filed Under: Banker's Discount

1 16075

Q:

In a 48 ltr mixture, the ratio of milk and water is 5:3. How much water should be added in the mixture so as the ratio will become 3:5 ?

A) 24 lit	B) 16 lit
C) 32 lit	D) 8 lit

Answer & Explanation Answer: C) 32 lit

Explanation:

Given mixture = 48 lit

Milk in it = 48 x 5/8 = 30 lit

=> Water in it = 48 - 30 = 18 lit

Let 'L' lit of water is added to make the ratio as 3:5

=> 30/(18+L) = 3/5

=> 150 = 54 + 3L

=> L = 32 lit.

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Filed Under: Alligation or Mixture
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

36 16048

Q:

The year next to 2003 will have the same calendar as that of the year 2003?

A) 2024	B) 2014
C) 2009	D) 2020

Answer & Explanation Answer: B) 2014

Explanation:

Given year 2003, when divided by 4 leaves a remainder of 3.

NOTE: When remainder is 3, 11 is added to the given year to get the result.

So, 2003 + 11 = 2014

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Filed Under: Calendar

36 16044

Q:

There are 5 novels and 4 biographies. In how many ways can 4 novels and 2 biographies can be arranged on a shelf ?

A) 26100	B) 21600
C) 24000	D) 36000

Answer & Explanation Answer: B) 21600

Explanation:

4 novels can be selected out of 5 in $5 C_{4}$ ways.

2 biographies can be selected out of 4 in $4 C_{2}$ ways.

Number of ways of arranging novels and biographies = $5 C_{4} * 4 C_{2}$ = 30

After selecting any 6 books (4 novels and 2 biographies) in one of the 30 ways, they can be arranged on the shelf in 6! = 720 ways.

By the Counting Principle, the total number of arrangements = 30 x 720 = 21600

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Filed Under: Permutations and Combinations

7 15989

Q:

What will be the compound interest on a sum of Rs.25,000 after 3 years at the rate of 12 p.c.p.a?

A) Rs.10123.20	B) Rs.12100
C) Rs.12552	D) Rs.12665

Answer & Explanation Answer: A) Rs.10123.20

Explanation:

Amount

= Rs.(25000x(1+12/100)³

= Rs.(25000x28/25x28/25x28/25)

= Rs. 35123.20.

C.I = Rs(35123.20 -25000)

= Rs.10123.20

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Filed Under: Compound Interest
Exam Prep: GRE

17 15949

Q:

There is certain numbers of toys in the box. They are divided into such a way that the person who gets 1/4 of the whole gets thrice of what the others get on an average. Find the number of people amongst whom the toys are distributed?

A) 8	B) 10
C) 12	D) 9

Answer & Explanation Answer: B) 10

Explanation:

If the person who gets 1/4 of the whole gets thrice of what the others get on an average, each one will get =1/3×1/4=112 of the whole.
Therefore, if there are k persons other than the person who gets one-fourth, then 1/4 + k/12 = 1
⇒ k=9

Hence, total number of people = 10.

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Filed Under: Ratios and Proportions

34 15938

Quantitative Aptitude - Arithmetic Ability Questions

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