Suppose a jar contains 8 balls among which 5 are red and 3 are blue.
If i pick, 3 balls from this jar, what is the probability that "exactly" two of them are blue ball?
[Math] Probability of picking balls from jar
binomial theoremprobability
binomial theoremprobability
Suppose a jar contains 8 balls among which 5 are red and 3 are blue.
If i pick, 3 balls from this jar, what is the probability that "exactly" two of them are blue ball?
Best Answer
The total number of ways to choose $3$ out of $8$ balls is $\binom83=56$
The number of ways to choose $2$ out of $3$ blue balls and $1$ out of $5$ red balls is $\binom32\cdot\binom51=15$
Hence the probability is $\dfrac{15}{56}$