6500+ Quantitative Aptitude Questions and Answers With Explanation

Q:

n is an integer chosen at random from the set

{5, 7, 9, 11 }

p is chosen at random from the set

{2, 6, 10, 14, 18}

What is the probability that n + p = 23 ?

A) 0.1	B) 0.2
C) 0.25	D) 0.3

Answer & Explanation Answer: A) 0.1

Explanation:

Each of the integers in the first set could be combined with any from the second set, giving a total of 4 x 5 = 20 possible pairs.

Of these the combinations that could give a sum of 23 are (5 + 18), and (9 + 14)

This means that the probability of getting a sum of 23 is 2/20 = 1/10

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Filed Under: Quantitative Aptitude - Arithmetic Ability
Exam Prep: GRE

0 47216

Q:

A basket contains 10 apples and 20 oranges out of which 3 apples and 5 oranges are defective. If we choose two fruits at random, what is the probability that either both are oranges or both are non defective?

A) 136/345	B) 17/87
C) 316/435	D) 158/435

Answer & Explanation Answer: C) 316/435

Explanation:

$n (s) = {}^{30}C_{2}$

Let A be the event of getting two oranges and

B be the event of getting two non-defective fruits.

and $(A \cap B)$ be the event of getting two non-defective oranges

$∴ P (A) = \frac{{}^{20}C_{2}}{{}^{30}C_{2}}, P (B) = \frac{{}^{22}C_{2}}{{}^{30}C_{2}} a n d P (A \cap B) = \frac{{}^{15}C_{2}}{{}^{30}C_{2}}$

$∴ P (A \cup B) = P (A) + P (B) - P (A \cap B)$

= $\frac{{}^{20}C_{2}}{{}^{30}C_{2}} + \frac{{}^{22}C_{2}}{{}^{30}C_{2}} - \frac{{}^{15}C_{2}}{{}^{30}C_{2}} = \frac{316}{435}$

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Filed Under: Probability

109 47115

Q:

A housewife saved Rs. 2.50 in buying an item on sale. If she spent Rs. 25 for the item, approximately how much percent she saved in the transaction ?

A) 8	B) 9
C) 10	D) 11

Answer & Explanation Answer: B) 9

Explanation:

Actual price = Rs. (25 + 2.50) = Rs. 27.50.

Saving = 2.50

Percentage Saving = [(2.50/27.50)*100]

= 2500/275

= $9 \frac{1}{11}$ %

$\approx 9$ %

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Filed Under: Percentage

111 46662

Q:

The length of a rectangle is halved, while its breadth is tripled. What is the percentage change in area?

A) 20%	B) 30%
C) 40%	D) 50%

Answer & Explanation Answer: D) 50%

Explanation:

Let original length = x and original breadth = y.

Original area = xy.

New length = x/2 and New breadth=3y

New area = $\frac{3}{2} x y$

Therefore, Increase in area = New area-original area = $\frac{3}{2} x y - x y = \frac{1}{2} x y$

Therefore, Increase % = $\frac{i n c r e a s e i n a r e a}{o r i g i n a l a r e a} * 100 = (\frac{\frac{1}{2} x y}{x y}) * 100 = 50$ %

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

47 46504

Q:

In a class, 30% of the students offered English, 20% offered Hindi and 10% offered both. If a student is selected at random, what is the probability that he. has offered English or Hindi ?

A) 1/2	B) 3/4
C) 4/5	D) 2/5

Answer & Explanation Answer: D) 2/5

Explanation:

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Filed Under: Probability

76 46376

Q:

A parallelogram has sides 30m and 14m and one of its diagonals is 40m long. Then its area is

A) 136	B) 236
C) 336	D) 436

Answer & Explanation Answer: C) 336

Explanation:

let ABCD be the given parallelogram

area of parallelogram ABCD = 2 x (area of triangle ABC)

now a = 30m, b = 14m and c = 40m

s=1/2 x (30+14+40) = 42

Area of triangle ABC = $\sqrt{[s (s - a) (s - b) (s - c)]}$

= $\sqrt{[42 (12) (28) (2)]}$ = 168sq m

area of parallelogram ABCD = 2 x 168 = 336 sq m

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

103 46320

Q:

Consider the figure shown below and choose the correct option for the length of MN.

A) d2-r1-r22	B) d2+r1-r22
C) d2-r1-r22	D) d+r1-r22

Answer & Explanation Answer: A) d2-r1-r22

Explanation:

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Filed Under: Simplification
Exam Prep: Bank Exams

0 46264

Q:

A can contains a mixture of two liquids A and B in the ratio 7 : 5. When 9 litres of mixture are drawn off and the can is filled with B, the ratio of A and B becomes 7 : 9. How many litres of liquid A was contained by the can initially?

A) 10	B) 20
C) 21	D) 25

Answer & Explanation Answer: C) 21

Explanation:

Suppose the can initially contains 7x and 5x litres of mixtures A and B respectively

Quantity of A in mixture left = $(7 x - \frac{7}{12} \times 9) = (7 x - \frac{21}{4})$ litres.

Quantity of B in mixture left = $(5 x - \frac{5}{12} \times 9) = (5 x - \frac{15}{4})$ litres.

$\frac{(7 x - \frac{21}{4})}{(5 x - \frac{15}{4}) + 9} = \frac{7}{9}$

$\Rightarrow \frac{28 x - 21}{20 x + 21} = \frac{7}{9}$

$\Rightarrow x = 3$

So, the can contained 21 litres of A.

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Filed Under: Alligation or Mixture

272 46260

Quantitative Aptitude - Arithmetic Ability Questions

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