#### Answer

$\frac{3}{4}$

#### Work Step by Step

The probability of event B, assuming that the event A has already occurred, is called the conditional probability of B, given A. This probability is denoted by P(B|A).
E: A red disk, given that an odd number is selected.
A: There are 4 odd numbered disks.
B: There are 3 disks that have odd numbers and are red.
Thus, we have:
P(B|A) = $\frac{3}{4}$