Question

Suppose x and y are real values that are distributed uniformly in the respective ranges 0≤x≤10 and 0≤y≤10. The probability that 8≤x+2y≤20 can be written as a/b, where a and b are coprime positive integers. Find a+b.

Answer 1

8 ≤ x+2y ≤ 20

8 -x ≤ 2y ≤ 20-x

4 -x/2 ≤ y ≤ 10-x/2

Answer 2

i got no idea what to do with that tho