Option B
Probability of drawing yellow marble followed by a red marble is 
<em><u>Solution:</u></em>
Given that a bag containing 12 yellow marbles, 16 red marbles, and 15 green marbles
So total number of marbles = 12 + 16 + 15 = 43
To find: probability of drawing yellow marble followed by a red marble if the first marble is not replaced
<em><u>The probability of an event is given as:</u></em>

<em><u>probability of drawing yellow marble followed by a red marble if the first marble is not replaced:</u></em>
First we pick up yellow marble.
Number of favorable outcomes = 12 yellow marbles
Total number of possible outcomes = 43 marbles

Now we have to pick red marble
But first marble is not replaced
So we have 43 - 1 = 42 number of possible outcomes
Favorable outcomes = 16 red marbles

So probability of drawing yellow marble followed by a red marble is:

Thus probability of drawing yellow marble followed by a red marble is 