How does spending on education and health help in removing investment bottlenecks?

The answer to your question is already covered in our study material. Follow the given link and scroll down to the topic 'Sources of human capital formation - Education and Health' to view the same.

https://www.meritnation.com/cbse/class11-commerce/studymaterial/economics/indian-economic-development/unit-iiihuman-capital-formation-in-india/442_2487_6384#slide1_meaning-of-human-capital-and-sources-of-human-capital-formation