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 10 of 11.
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.
Naina said:
8 years ago
A coin is tossed live times. What is the probability that there is at the least one tail?
Can anyone help me with this question?
Can anyone help me with this question?
Thrideep said:
8 years ago
I think The answer is 3/4.
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.
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.
Azoya said:
7 years ago
Multiple of 3 = {3,6,9,12,15,18},
Multiple of 5 ={5,10,15},
Multiple of both 3 and 5 = {15},
So p(3) = 6/20,
p(5) = 3/20,
p(3 and 5) = 1/20.
So, answer is = 6/20 + 3/20 -1/20.
i,e. 8/20 which is 2/5 according to options.
I am getting this answer because the question is multiple of 3 or 5 . So we need to exclude multiple of 3 and 5.
Multiple of 5 ={5,10,15},
Multiple of both 3 and 5 = {15},
So p(3) = 6/20,
p(5) = 3/20,
p(3 and 5) = 1/20.
So, answer is = 6/20 + 3/20 -1/20.
i,e. 8/20 which is 2/5 according to options.
I am getting this answer because the question is multiple of 3 or 5 . So we need to exclude multiple of 3 and 5.
Deepika Balaji said:
7 years ago
Can anyone help me in solving this problem. What is the probability of getting at least one six in a single throw of three unbiased dice?
Asiya said:
7 years ago
My answer is 8/20 because in question it is stated that we take multiple of 3 or 5 not multiple of both so we should neglect 15 because it is the multiple of 3 and 5.
Anyone please help me to get it.
Anyone please help me to get it.
Siva said:
7 years ago
How come 4/20 & 6/20?
V S Abhirame said:
7 years ago
@Souravbaidya.
Circular board of i feet has area Pi. The area of the region containing all points which are closed to center than to periphery will be Pi/4. Hence the proportion to hit near the center is 1/4=.25. So, D is the correct answer.
Circular board of i feet has area Pi. The area of the region containing all points which are closed to center than to periphery will be Pi/4. Hence the proportion to hit near the center is 1/4=.25. So, D is the correct answer.
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