Bank PO Questions and Answers with Explanation, Job Roles

Q:

If the mean of a, b, c is M and ab + bc + ca = 0, then the mean of $\frac{a^{2} + b^{2} + c^{2}}{3}$ is :

A) M	B) 3 M^2
C) 2 (M/3)	D) M^2

Answer & Explanation Answer: B) 3 M^2

Explanation:

We have : ( a + b + c) / 3 = M or (a + b + c) = 3M.

Now. ${(a + b + c)}^{2} = {(3 M)}^{2} = 9 M^{2}$ .

$< = > a^{2} + b^{2} + c^{2} + 2 (a b + b c + c a) = 9 M^{2}$

$a^{2} + b^{2} + c^{2} = 9 M^{2}, (a b + b c + c a = 0)$

Required mean = $(\frac{a^{2} + b^{2} + c^{2}}{3}) = \frac{9 M^{2}}{3} = 3 M^{2}$ .

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

35 28676

Q:

If the length of a certain rectangle is decreased by 4 cm and the width is increased by 3 cm, a square with the same area as the original rectangle would result. Find the perimeter of the original rectangle.

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

Answer & Explanation Answer: D) 50

Explanation:

Let x and y be the length and breadth of the rectangle respectively.
Then, x - 4 = y + 3 or x - y = 7 ----(i)
Area of the rectangle =xy; Area of the square = (x - 4) (y + 3)
(x - 4) (y + 3) =xy <=> 3x - 4y = 12 ----(ii)
Solving (i) and (ii), we get x = 16 and y = 9.
Perimeter of the rectangle = 2 (x + y) = [2 (16 + 9)] cm = 50 cm.

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

21 28617

Q:

A bag contains 4 red and 3 black balls. A second bag contains 2 red and 4 black balls. One bag is selected at random. From the selected bag, one ball is drawn. Find the probability that the ball drawn is red.

A) 23/42	B) 19/42
C) 7/32	D) 16/39

Answer & Explanation Answer: B) 19/42

Explanation:

A red ball can be drawn in two mutually exclusive ways

(i) Selecting bag I and then drawing a red ball from it.

(ii) Selecting bag II and then drawing a red ball from it.

Let E1, E2 and A denote the events defined as follows:

E1 = selecting bag I,

E2 = selecting bag II

A = drawing a red ball

Since one of the two bags is selected randomly, therefore

P(E1) = 1/2 and P(E2) = 1/2

Now, $P (\frac{A}{E_{1}})$ = Probability of drawing a red ball when the first bag has been selected = 4/7

$P (\frac{A}{E_{2}})$ = Probability of drawing a red ball when the second bag has been selected = 2/6

Using the law of total probability, we have

P(red ball) = P(A) = $P (E_{1}) \times P (\frac{A}{E_{1}}) + P (E_{2}) \times P (\frac{A}{E_{2}})$

= $\frac{1}{2} \times \frac{4}{7} + \frac{1}{2} \times \frac{2}{6} = \frac{19}{42}$

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

64 28522

Q:

Pointing to a woman, a man said, "Her father is the only son of my father." How is the man related to the woman?

A) Father	B) Brother
C) Uncle	D) Brother-in-law

Answer & Explanation Answer: B) Brother

Explanation:

The man said, "Her father is the only son of my father."

Then the woman's father and the man's is the same

=> The woman and the man are brother and sisters.

Hence, the man is the brother of the woman.

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Filed Under: Blood Relations
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

58 28514

Q:

In a queue, Amrita is 10th from the front while Mukul is 25th from behind and Mamta is just in the middle of the two. If there be 50 persons in the queue. What position does Mamta occupy from the front ?

A) 14th	B) 16th
C) 18th	D) 20th

Answer & Explanation Answer: C) 18th

Explanation:

Number of persons between Amrita and Mukul = 50 - (10 + 25) = 15. Since Mamta lies in middle of these 15 persons, so Mamta`s position is 8th from Amrita i.e. 18th from the front.

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Filed Under: Number, Ranking and Time Sequence Test
Exam Prep: AIEEE , Bank Exams , CAT , GATE , TOEFL
Job Role: Bank Clerk , Bank PO

102 28510

Q:

A watch gains 5 seconds in 3 minutes and was set right at 8 AM. What time will it show at 10 PM on the same day ?

A) 10 : 27 : 41 AM	B) 8 : 51 : 04 AM
C) 9 : 45 : 15 PM	D) 10 : 23 : 20 PM

Answer & Explanation Answer: D) 10 : 23 : 20 PM

Explanation:

The watch gains 5 seconds in 3 minutes = 100 seconds in 1 hour.

From 8 AM to 10 PM on the same day, time passed is 14 hours.

In 14 hours, the watch would have gained 1400 seconds or 23 minutes 20 seconds.

So, when the correct time is 10 PM, the watch would show 10 : 23 : 20 PM

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

46 28397

Q:

What time will it be 18 hours from now in India, if in the USA it is 4:15 AM?

(Hint : IST = US + 9:30 hrs)

A) 1:45 in the afternoon	B) 7:45 in the evening
C) 7:45 in the next morning	D) 1:45 in the next morning

Answer & Explanation Answer: C) 7:45 in the next morning

Explanation:

We know that the time difference between India and USA is 9 hrs 30 min.

India is 9:30 hrs ahead of USA.

Time in India = 4:15 + 9:30 = 13:45 PM.

Required Time after 18 hrs = 13:45 + 18 hrs = 7:45 AM.

Hence it is 7:45 AM on the next morning.

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Filed Under: Clocks
Exam Prep: AIEEE , Bank Exams , CAT , GRE , TOEFL
Job Role: Analyst , Bank Clerk , Bank PO , Database Administration , IT Trainer , Network Engineer

20 28382

Q:

A man traveled from the village to the post-office at the rate of 25 kmph and walked back at the rate of 4 kmph. If the whole journey took 5 hours 48 minutes, find the distance of the post-office from the village ?

A) 40 km	B) 30 km
C) 20 km	D) 10 km

Answer & Explanation Answer: C) 20 km

Explanation:

Average speed = $\frac{2 a b}{a + b}$ , here a=25 b=4
= 2 x 25 x 4/(25+4) = 200/29 km/hr.

Distance covered in 5 hours 48 minutes
= Speed x time = (200/29)x (29/5) Distance covered in 5 hours 48 minutes = 40kms.

Distance of the post office from the village = (40/2) = 20 km.

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

32 28365

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