Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 1)
1.
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?
Answer: Option
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) | = | 9 | . |
| n(S) | 20 |
Discussion:
107 comments Page 7 of 11.
Saiful Islam said:
1 decade ago
Actually, I don't understand your explanation boss. Please explain elaborately. How can it will be 9/20?
Shashi said:
8 years ago
Since the number of events are 20.
So possible events are {3,6,9,12,15,18,5,10,20}.
So answer is 9/20.
So possible events are {3,6,9,12,15,18,5,10,20}.
So answer is 9/20.
Goutam said:
8 years ago
9/20 is correct answer.
5 multiplies are 5,10,15,20.
3 multiplies are 3,9,12,15,18.
Answer = 9/20.
5 multiplies are 5,10,15,20.
3 multiplies are 3,9,12,15,18.
Answer = 9/20.
Abhishek tomar said:
3 years ago
15 is the multiple of 3 and 5. while question is about the multiple of 3 or 5 so, why not option C?
(9)
Anonymous said:
7 years ago
Why didnt we apply the (not A) formula?
i.e. (Not blue ball) = 1 - (blue ball).
= 1 - 2/7.
= 5/7.
i.e. (Not blue ball) = 1 - (blue ball).
= 1 - 2/7.
= 5/7.
Kavana said:
9 years ago
From 1 to 340, the probability of getting multiples of 8 and 5 is? Please answer this question.
Satyendra Shukla said:
1 decade ago
Answer will be 9/20, because 15 already be considered, so it can not be consider next time.
Naana said:
1 decade ago
Please how do you come about the 1/2 (ie A intersection B) ? I am a bit confused.
Thanks.
Thanks.
Ephrem Alemu Mantose ETH said:
2 years ago
The answer is correct.
P(A U B) = P(A) + P(B) - P(AnB),
= 6/20 + 4/20 - 1/20,
= 9/20.
P(A U B) = P(A) + P(B) - P(AnB),
= 6/20 + 4/20 - 1/20,
= 9/20.
(18)
Veeru said:
1 decade ago
Sundar & Manju thought wrong because 15 already be consider.
So ans will be 9/20.
So ans will be 9/20.
(1)
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