Invoice

Hi. 

Customer A purchases from me two products. One product is exempted and another one is taxable. 

So do I need to issue different invoices for exempted and taxable goods?

one bill containing both the products is sufficient?

GST act says bill of supply for exempted goods? But how can I issue two bills for two different products on basis of their taxability. It would be time consuming. 

Please guide. 

Thanks