How can i check how many classes are covered by a single test Class?

First of all, it is highly unadvisable to not use limits ,i.e., test.startTest()/test.stopTest() operators. Not only is it wrong testing practice, it creates lots of problem later on (like you are facing now).
With that said
It's not possible to track which test class covers which class and by how much percentage. You can figure out the percentage of coverage for a class but cannot track how much is covered by a single test class. You can also not figure out how much a test class cover.
The workaround is to track all fired triggers, and trace outputs of all triggers. You can do that through debug logs. If you test fails you will get a trace of classes the test connected and at which point it failed.

Developer Console > File > Open > 'Select class', top left corner says which tests are covering the specific class and the percentage of coverage of each class.

Thanks