Answer: The disk selected is one of those 6. Three are red, three are yellow. Therefore, there are 3 chances out of 6 that the disk will be yellow, which reduces to 1/2 or 0.50.
Step-by-step explanation: The short answer is that the numbers given determine the disk, not the fact that two disks are being chosen. There are 6 possible numbers chosen, and half of them will produce a yellow.
The longer answer is that these are not independent events, which would allow one to multiply the probability. The number and the disk are not independent; one determines the other. There is a probability of getting a yellow of 4/10 with the first choice, and then it is 3/9. But the choices are CONDITIONAL upon a certain number's being allowed
