QuickTest Professional (QTP) Question:

Answer #1
1. Recording a scenerio in QTP of my web based application.
2. Make 100 copies of that scenerio and run the test (scenerio run for 100 times)
3. In that case, do the load of application on server.
4. The basic logic of running the copy 100 times is to create same scenerio as if 100 users were working.

Answer #2
You can of course write a script in QTP for say logging into a website and run that script via loadrunner.
But firstly, the time will not be exact as QTP will add its own time (for execution) to the response time.
Secondly you will be able to simulate only one user per machine, while as Load runner simulates hundreds of users at a time.