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### Someone ans it.

Posted: **Wed Feb 20, 2019 8:55 am**

by **NABILA**

Imagine you have $5$ green and $5$ blue balls in a box. 2 balls are taken from the box what is the probability of at least one ball will be blue. What is the probability of those two balls will green

### Re: Someone ans it.

Posted: **Wed Feb 20, 2019 9:11 am**

by **samiul_samin**

Probablity of at least $1$ ball is blue=$\dfrac{\dbinom{5}{1}×\dbinom {5}{1}+\dbinom {5}{2}x\dbinom {5}{0}

}{\dbinom {10}{2}}=\dfrac 79$

Probablity of $2$ ball is green=$\dfrac{\dbinom {5}{2}×\dbinom{5}{0}}{\dbinom {10}{2}}=\dfrac 29$