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# A Pair Of Unbiased Dice Is Rolled Together Till A Sum Of Either 5 Or 7 Is Obtained. The Probability That 5 Comes Before 7 Is

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## Question

### Solution

Correct option is

2/5

Let A denote the event that a sum of 5 occurs, B the event that a sum of 7 occurs and C the event that neither a sum of 5 nor a sum of 7 occurs. We have

Thus,

P (A occurs before B)

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