Math is good. Come on in.

Question 1: The probability of rain on Saturday is 0.5, and the probability of no rain on Saturday is 0.5.

The probability of rain on Sunday is 0.8, and the probability of "no" rain on Sunday is 0.2.

Then the probability of just one day =0.5*0.2+0.5*0.8=0.5.

Question 2: First of all, the possibility of even numbers on the dice is 1/2.

Then the probability of simultaneous occurrence is (1/2) 4 =116.

The third question: this question can actually be worked out by making a list, which may all be 4*5=20 kinds.

There are five cases where the number of components cannot form the simplest fraction: 2/4, 2/6, 3/6, 4/4, 5/5 * *.

Therefore, the probability that the number of components just constitutes the simplest fraction =(20-5)/20=3/4.