Answer:
p(green) = 3/10
p(red) = 5/10
(you can of course reduce)
Step-by-step explanation:
Probability is just a big word for a simple concept
Probability of green marbles = number of green marbles over total number of marbles.
Probability of red marbles = number of red marbles over total number of marbles.
Don't over complicate it :)