CAN SOMEONE PLEASE HELP ME I'M STUCK. PLEASE
I don't understand and know how to solve it.

Answer:
7/10
Step-by-step explanation:
red + green = 50 + 20 = 70 marbles
Total marbles = 50 + 30 + 20 = 100 marbles
P(red or green) = 70/100
P(red or green) = 7/10