Probability
- Two dice are thrown simultaneously. What is the probability of getting a number other than 4 on any dice ?
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Here, n(S) = 6 x 6 = 36 and E = Event of getting a number other than 4 on any dice
= {(1, 1), (1, 2), (1, 3), (1, 5), (1, 6), (2, 1), (2, 2) , (2, 3) , (2, 5), (2, 6), (3, 1), (3, 2), (3, 3), (3, 5), (3, 6), (5, 1) , (5, 2) , (5, 3), (5, 5), (5, 6), (6, 1), (6, 2), (6, 3), (6, 5), (6, 6) }Correct Option: A
Here, n(S) = 6 x 6 = 36 and E = Event of getting a number other than 4 on any dice
= {(1, 1), (1, 2), (1, 3), (1, 5), (1, 6), (2, 1), (2, 2) , (2, 3) , (2, 5), (2, 6), (3, 1), (3, 2), (3, 3), (3, 5), (3, 6), (5, 1) , (5, 2) , (5, 3), (5, 5), (5, 6), (6, 1), (6, 2), (6, 3), (6, 5), (6, 6) }
∴ P(E) = n(E) / n(S) = 25/36
- Number 1 to 25 are marked on tokens of equals size one on each. A token is drawn at random. Find the probability of getting a number divisible by both 2 and 3?
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Total number of ways of selecting one number from 25 number is 25C1 ways.
Let E be the event of drawing a number divisible by both 2 and 3
i.e., (if a number is divisible by both 2 and 3, it is divisible by 6 also)Correct Option: A
Total number of ways of selecting one number from 25 number is 25C1 ways.
Let E be the event of drawing a number divisible by both 2 and 3
i.e., (if a number is divisible by both 2 and 3, it is divisible by 6 also)
E = {6, 12, 18, 24}
∴ Required probability = P(E) = n(E) / n(S) = 4/25
- A complete cycle of a traffic light takes 60 s. During each cycle the light is green for 25 s, yellow for 5 s and red for 30 s. At a randomly chosen time, the probability that the light will not be green is ?
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Probability that light will be green = (Time for which light is green)/(time taken for complete cycle)
Correct Option: D
Time taken for complete cycle = 60 s
Probability that light will be green = (Time for which light is green)/(time taken for complete cycle)
= 25/60 = 5/12
∴ Probability that light will not be green = 1- 5/12 = 7/12
- The probability that a man will live 10 more year is 1/4 and the probability that his wife will live 10 more year is 1/3. Then, the probability that none of them will be alive after 10 yr, is ?
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Let the name of the man be A and that of his wife be B. Then ,P(A will not be alive after 10 yr and B will not be alive after 10yr) = 3/4 x 2/3 = 1/2
Correct Option: B
Let the name of the man be A and that of his wife be B. Then ,P(A will not be alive after 10 yr and B will not be alive after 10yr) = 3/4 x 2/3 = 1/2
- The letters B, G, I, N, R are rearranged to form the word 'BRING'. Find its probability ?
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The five letters could be arrange in 5! ways.
One of them is 'BRING'.Correct Option: A
The five letters could be arrange in 5! ways.
One of them is 'BRING'.
∴ Required probability = 1/5!
= 1/(5 x 4 x 3 x 2 x 1)
= 1/120