with a 100 amp panel, would that mean i could get 10 miners going with 240 volts, and would have only been able to get 5 miners at 120 volts?
Yes.
No.
Based on the voltages mentioned, I assume Jerry is in North America. The incoming residential power (three wires) is 240 volts at 60 Hz with a center tap. The center tap conductor is earthed and called "Neutral". The other two wires are both called "Hot". From one Hot to Neutral is 120 volts. From Neutral to the other Hot, it is also 120 volts. Connecting across both Hots (and ignoring the Neutral) gives 240 volts.
Current entering via one conductor has to leave via a different conductor. Also, the topology means that the current in the Neutral is the
difference in the currents in the Hots.
A 100 amp panel means Jerry can draw a max of 100 amps on any of the three conductors. This could be achieved by a 100 amp 120 volt load connected between one Hot and the Neutral. Or it could be a 100 amp 240 volt load connected across the Hots. Or it also be a 100 amp 120 volt load connected between one Hot and the Neutral
and another 100 amp 120 volt load connected between Neutral and the other hot. In the last two cases, the current in the Neutral is
zero!
Thus Jerry could have ten 240 volt miners. Or five 120 volt miners on one hot and five more 120 volt miners on the other hot. So - ten miners either way.
Jerry: You could have an electrician install a row of 240 volt receptacles. Nominally, two receptacles could be paired together on one circuit beaker. Because this is a 240 volt breaker, it will be double width taking up two spots in the breaker panel.
Alternately, you could have a row of 120 volt receptacles installed. The current requirements mean that each receptacle will need its own (single wide) circuit breaker. Depending on what brand of breakers you have, you may be able to use half width breakers to power two receptacles from one spot in the panel.
A row of 240 volt receptacles will be useless to anyone else in the future. Contrastingly, the 120 volt receptacles could be useful to someone running servers.