The answer to question above is 0.0000593
Given:
Planes X and Y are perpendicular to each other
Points A, E, F, and G are points only in plane X
Points R and S are points in both planes X and Y
Lines EA and FG are parallel
The lines which could be perpendicular to RS are EA and FG.
20.16 hopefully it’s right
Answer:

And then replacing in the total probability formula we got:

And rounded we got 
That represent the probability that it rains over the weekend (either Saturday or Sunday)
Step-by-step explanation:
We can define the following notaton for the events:
A = It rains over the Saturday
B = It rains over the Sunday
We have the probabilities for these two events given:

And we are interested on the probability that it rains over the weekend (either Saturday or Sunday), so we want to find this probability:

And for this case we can use the total probability rule given by:

And since we are assuming the events independent we can find the probability of intersection like this:

And then replacing in the total probability formula we got:

And rounded we got 
That represent the probability that it rains over the weekend (either Saturday or Sunday)