Update README.md

Pegah-Ardehkhani · web-flow · commit f663b00e753a · 2024-12-10T12:04:41.000+03:30
diff --git a/README.md b/README.md
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 # Optimization Problems and Solutions ![license](https://img.shields.io/github/license/Pegah-Ardehkhani/Optimization-Problems-and-Solutions.svg) ![releases](https://img.shields.io/github/release/Pegah-Ardehkhani/Optimization-Problems-and-Solutions.svg)
 
+> **`Note`**: Problems 19, 21, and 22 are solved with Python, CPLEX, and R, while the others use Python only.
+
 > **`Note`**: This repository is still developing.
 
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