Answer:
75%
Explanation:
The number of red marbles, n(R) = 4
Total number of marbles, n(S) = 4+1+2+6+3 = 16
The probability of not picking a red marble, P(R'):
[tex]\begin{gathered} P(R^{\prime})=1-P(R) \\ =1-\frac{n(R)}{n(S)} \\ =1-\frac{4}{16} \\ =1-\frac{1}{4} \\ =\frac{3}{4} \\ =0.75 \\ =75\% \end{gathered}[/tex]The probability of picking a marble that is not a red marble is 75%.