the numbered disks shown are placed in a box and one disk is selected at random. find the probability of…

Explanation:

Step1: Count green disks

There are 5 green disks (1, 3, 4, 5, 7).

Step2: Count green - even disks

Among the green disks, the even - numbered one is 4. So there is 1 green - even disk.

Step3: Calculate conditional probability

The formula for conditional probability $P(A|B)=\frac{n(A\cap B)}{n(B)}$, where $A$ is the event of selecting an even number and $B$ is the event of selecting a green disk. Here, $n(A\cap B) = 1$ (the green - even disk) and $n(B)=5$ (total green disks). So the probability is $\frac{1}{5}$.

Answer:

$\frac{1}{5}$