could it be helpful to server static data using Nginx(Images,css,js) and dynamic data (Application code+database) using Apache ?
It's helpful. Some benchmarks have proven nginx to become a minimum of two times as quickly as Apache at static content.
Based on the application it may be. The concept is, that the application may contain multiple static demands per page. If you're able to answer these having a small memory footprint Nginx you might finish up requiring less Apache employees that will most likely possess a greater memory footprint for the similar quantity of traffic.
It is also helpful due to keep-alive tearing.
Imagine browser's http request a large dynamic ammount of information. Client's network connection is a lot reduced than internal networking (most typical situation when nginx and apache on the same host, so that they conveys via loopback interface). Apache submitted all data towards the nginx and it is worker is able to serve the following request extremely fast while nginx delivering that data towards the client.
Due to nginx's speed and footprint it may handle a lot more connections simultaniously which means this symbiosis is effective.