Can i get a ride with cash only?
The Guru Take
Not usually. In some regions, yes.
(UPDATED: Here's a more recent RideGuru answer: What Uber services can I pay using cash?)
For taxis, yes, almost all companies/drivers in all location would accept cash.
If you are referring to Uber and Lyft, they currently do not allow you to pay in cash, as the mobile app requires you to have your credit card or debit card in the system.
There are certain Uber services and in certain regions, cash can be used in lieu of the credit card on file. They are usually local taxis that you dispatch through Uber app, and they are more common in India and Southeast Asia.