rxjs/Subject.d.ts error : Class 'Subject' incorrectly extends base class 'Observable'

Question

I extracted sample template code from this tutorial and did below two steps to get started -

1. npm install // worked fine and created node_modules folder

Answer 1

GO to Package.json file and modify the below configuration

...
  "rxjs": "5.4.1",
  "typescript": "~2.4.0"
...

It will work