Plumbing A Two Sink Lavatory.

I am helping my son do some remodeling to his home and have encountered the following.

I one of the bathrooms he had a long vanity with a single sink. We replaced it with a vanity with 2 sinks.

There is only one waste pipe. What do I need to plumb the two sinks to this pipe. i.e. do I need a p-trap at each sink or just one at the waste pipe?

Thanks,

Charles

PS A diagram would really help.

One trap only. Bring the two sinks together with a tee.

Thank you very much for the help.