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Probability - Quant/Math - CAT 2008
Question 4 the day:
March , 2003
The question for the day is from the topic of Probability
- When two dice are thrown simultaneously, what is the probability that the sum of the two numbers that turn up is less than 11?
| (1) |
5 / 6 |
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(2) |
11 / 12 |
| (3) |
1 / 6 |
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(4) |
1 / 12 |
Correct Answer - (2)
Solution:
Instead of finding the probability of this event directly, we will find the probability of the non-occurrence of this event and subtract it from 1 to get the required probability.
Combination whose sum of 12 is (6,6)
Combinations whose sum of 11 is (5,6), (6,5).
Therefore, there are totally 3 occurrences out of 36 occurrences that satisfy the given condition.
Probability whose sum of two numbers is greater than or equal to 11 = 3 / 36 = 1 / 12.
Hence probability whose sum of two numbers is lesser than 11 = 1 - 1 / 12 = 11 / 12.
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