Answer
$\frac{2}{7}$
Work Step by Step
The events are dependent because the marbles are not replaced
4 of the 7 marbles are red:
P(red)=$\frac{4}{7}$
3 of the 6 remaining marbles are red:
P(red after red)=$\frac{3}{6}$=$\frac{1}{2}$
P(red then red)=P(red) $\times$ P(red after red)
P(red then red)=$\frac{4}{7}$ $\times$ $\frac{1}{2}$
P(red then red)=$\frac{2}{7}$