The probability that a blue-eyed person is left-handed is $\frac{1}{7}$.
The probability that a left-handed person is blue-eyed is $\frac{1}{3}$ .
The probability that a person has neither of the attributes is $\frac{4}{5}$.
What is the probability that a person has both attributes?
I just don't know how they got the answer
Answer: $\frac{1}{45}$
Best Answer
Hint:
$P\left[L\mid B\right]=\frac{1}{7}$ i.e. $P\left[L\cap B\right]=\frac{1}{7}P\left[B\right]$
$P\left[B\mid L\right]=\frac{1}{3}$ i.e. $P\left[L\cap B\right]=\frac{1}{3}P\left[L\right]$
$1-P\left[L\cup B\right]=\frac{4}{5}$
These equations are enough to find $P\left[L\cap B\right]$