To solve the inequality \(15y - 9 < 36\), we will follow a step-by-step process.
1. Start with the given inequality:
[tex]\[
15y - 9 < 36
\][/tex]
2. Add 9 to both sides of the inequality to isolate the term with \(y\) on the left side:
[tex]\[
15y - 9 + 9 < 36 + 9
\][/tex]
This simplifies to:
[tex]\[
15y < 45
\][/tex]
3. Divide both sides by 15 to solve for \(y\):
[tex]\[
\frac{15y}{15} < \frac{45}{15}
\][/tex]
Simplifying, we get:
[tex]\[
y < 3
\][/tex]
Thus, the solution set of the inequality \(15y - 9 < 36\) is:
[tex]\[
y < 3
\][/tex]
Therefore, the correct answer is:
[tex]\[
\boxed{y < 3}
\][/tex]