You have to find a common denominator for both fractions. I chose the denominator to be 10, so the 1/2 will become 5/10, and 1/5 will become 2/10.
Subtract 5/10 from 2/10. You will get -3/10.
Answer: -3/10
You can check your answer by solving 1/2-3/10=1/5 to see if it is true. (It is:)
Answer:
I would divide 50 by 4 (Because there are usually 4 weather conditions in game) and whichever the number is closest to it would pick that weather condition
The answer for your question is 12/15