Explain all the working of investment multiplier with the help of a numerical example .

The answer to your question is already covered in our study material. Follow the given link and scroll down to the topic 'Operation of investment multiplier' to view the same.

https://www.meritnation.com/cbse/class12-commerce/studymaterial/economics/introductory-macroeconomics/income-determination/341_1989_5846#slide4_multiplier-mechanism-and-paradox-of-thrift