Let the total number of employees in the organization be \( N \).
- 40% of the employees are matriculates, so the number of matriculate employees is:
\[
\text{Matriculates} = 0.40N
\]
- 50% of the remaining employees (i.e., 60% of the total) are graduates. The remaining 225 employees are post-graduates.
Now, the number of employees who are not matriculates is \( 0.60N \). Since 50% of them are graduates, the number of graduates is:
\[
\text{Graduates} = 0.50 \times 0.60N = 0.30N
\]
The remaining employees are post-graduates, and their number is 225. Therefore, we have:
\[
\text{Post-graduates} = 0.60N - 0.30N = 0.30N = 225
\]
Solving for \( N \):
\[
0.30N = 225 \quad \Rightarrow \quad N = \frac{225}{0.30} = 750
\]
Thus, the number of matriculate employees is:
\[
\text{Matriculates} = 0.40 \times 750 = 300
\]