A die is tossed twice A success is getting an odd number on a toss. Find the variance of the number of successes.

Answer

Variance, `var(X)=1/2`

Explanation

When a fair dice is thrown twice the total possible outcomes is 36


Let `X` denote a success is getting an odd number on a toss.


`therefore X` can take values `0,1,2`


Now the probability of drawing the odd number appears on the dice:


`P(X=0)=P("no odd number or all even number both time"),`

`=3/6 times 3/6=1/2 times 1/2=1/4`


`rArr P(X=0)=1/4`


`P(X=1)=P("odd number once"),`

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