It's very difficult to say as this would differ in every environment depending on the products installed. Best way to identify which application server host which sas apps is to use the instructions.html file that would be created after configuration of your mid-tier at location <sas-config>/Lev1/Documents/. Open this file and navigate to "Configuring your SAS Web Application Server Instances" section. Under this section, you will see all your web application server instances and the web applications deployed to it.
If you don't have access to this file, then you can navigate indiviually to each web applications server path: <sas-config>/Lev1/Web/WebAppServer/SASServerX_X/sas_webapps/ to find the applications deployed and make a note of it.