Answer:
2/3
Step-by-step explanation:
Total number of marbles = 3 + 4 + 5 = 12
Pr (red marble) 3/12
Pr (Blue marble) = 4/12
Pr (white marble) = 5/12
Probability of drawing either a red or a white marble
= Pr ( red) + Pr (white)
= 3/12 + 5/12
= 8/12
= 2/3
