Question 1172049
<pre>
The probability that the first marble is not a red one is:

11 non-red marbles out of 15, that's a probability of 11/15.

Now there are only 14 marbles in the jar.  The second one is also not a red one.

10 non-red marbles out of 14, that's a probability of 10/14.

So the probability that both events occur in order is (11/15)(10/14) = 11/21.

Edwin</pre>