Moonfrog Interview Questions | Probablity
Question
What is the probability of getting 2 numbers whose products are even when two dices were thrown?
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Statistics
55 years
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Answers ( 2 )
Products are even in 2 cases.
1) When even is multiplied by even.
2) When odd is multiplied by even.
so, the total no of such cases are
(1,2),(1,4),(1,6)
(2,1),(2,2),(2,3),(2,4),(2,5),(2,6)
(3,2),(3,4),(3,6)
(4,1),(4,2),(4,3),(4,4),(4,5),(4,6)
(5,2),(5,4),(5,6)
(6,1),(6,2),(6,3),(6,4),(6,5),(6,6)
so, 27/36 = 3/4
We know the product will be odd if and only if both the numbers in the dice are odd. In all other cases (odd,even), (even,odd), (even,even) the product will be even. Now,
The probability that the product will be even= 1 – probability that both the numbers will be odd
The probability that both the numbers will be odd= 3/6 * 3/6 =9/36
Hence the req probability=1- 9/36 = 27/36