1. The probability of the first yellow ball draw is1/3; The probability of winning the yellow ball for the second time is1/5;

The probability that both balls are yellow balls is1/3 *1/5 =115.

2. Suppose a certain color is extracted for the first time, and the probability of not extracting this color for the second time is 4/5.

So the probability of two different colors is 4/5.