Answer:
[tex]\huge\boxed{\sf \frac{5}{15} + \frac{4}{14} }[/tex]
Step-by-step explanation:
Total number of marbles = 5 + 8 + 2 = 15
Number of red marbles = 5
Probability to draw a red marble at the first trial = 5/15
Number of marbles left = 15 - 1 = 14
Number of Red marbles left = 5 - 1 = 4
Probability to draw a red marble at the second trial = 4/14
[tex]\displaystyle =Probability \ of \ drawing \ a \ red \ marble \ at \ the \ (second \ attempt +first \ attempt)\\\\= \frac{5}{15} + \frac{4}{14} \\\\\rule[225]{225}{2}[/tex]