Can an Arduino power another Arduino (and/or an ATTiny chip)?

Projects General Guidance
1

Can I run a wire from 5V (and ground) on an Arduino to the Vin of another Arduino and/or an ATTiny chip?

Thanks!

2

I am not sure if the voltage regulators onboard the various Arduinos are the same, but I am running 60 ma. worth of peripherals out of the 5v. pin on a nano.

3

I often connect two Arduinos together, however I just connect 5v on one to 5v on the other (plus Gnd of course).