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Q:

A number is selected from the numbers 1,2,3,4.......25.The probability for it to be divisible by 4 or 7 is:

A) 3/25 B) 9/25
C) 1/25 D) None of these
 
Answer & Explanation Answer: B) 9/25

Explanation:

Total numbers = 25

 Numbers divisible by 4 or 7 are 4, 7, 8, 12, 14, 16, 20, 21, 24 = 9

 

 The probability (divisible by 4 or 7) = 9/25

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Filed Under: Probability

Q:

Two dice are tossed. The probability that the total score is a prime number is:

A) 5/12 B) 1/6
C) 1/2 D) 7/9
 
Answer & Explanation Answer: A) 5/12

Explanation:

Clearly, n(S) = (6 x 6) = 36.

Let E = Event that the sum is a prime number.

Then E= { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4,3),(5, 2), (5, 6), (6, 1), (6, 5) }

n(E) = 15.

P(E) = n(E)/n(S) = 15/36 = 5/12.

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Filed Under: Probability

Q:

Two dice are thrown simultaneously. What is the probability of getting two numbers whose product is even?

A) 3/4 B) 3/8
C) 5/16 D) 2/7
 
Answer & Explanation Answer: A) 3/4

Explanation:

In a simultaneous throw of two dice, we have n(S) = (6 x 6) = 36.

Then, E= {(1, 2), (1, 4), (1, 6), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6), (3, 2), (3,4),(3, 6), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (5, 2), (5, 4), (5, 6), (6, 1),6, 2), (6, 3), (6, 4), (6, 5), (6, 6)}

n(E) = 27.

P(E) = n(E)/n(S) = 27/36 = 3/4.

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Filed Under: Probability

Q:

What would be the least number of years in which the simple interest on Rs.2600 at % will be an exact number of rupees ?

A) 2 B) 3
C) 4 D) 5
 
Answer & Explanation Answer: B) 3

Explanation:

 S.I=Rs.2600*203*1100*t

 S.I=Rs.5203*t

 t=3

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Filed Under: Compound Interest
Exam Prep: Bank Exams
Job Role: Bank PO

Q:

Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?

A) 1/2 B) 3/5
C) 9/20 D) 8/15
 
Answer & Explanation Answer: C) 9/20

Explanation:

Here, S = {1, 2, 3, 4, ...., 19, 20}.

Let E = event of getting a multiple of 3 or 5 = {3, 6 , 9, 12, 15, 18, 5, 10, 20}.

P(E) = n(E)/n(S) = 9/20.

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Filed Under: Probability

Q:

The least number of complete years in which a sum of money put out at 20% compound interest will be more than doubled is:

A) 3 B) 4
C) 5 D) 6
 
Answer & Explanation Answer: B) 4

Explanation:

 

 P1+20100n>2P65n>2

 65×65×65×65>2

 

so, answer is 4 years

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Filed Under: Compound Interest
Exam Prep: Bank Exams
Job Role: Bank PO

Q:

The isotopes of chlorine with mass number 35 and 37 exist in the ratio of

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

Explanation:
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Filed Under: Chemistry

Q:

In known elements, the maximum number is of

A) Metals B) Non Metals
C) Metalloids D) None of these
 
Answer & Explanation Answer: A) Metals

Explanation:
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Filed Under: Chemistry