1 I was watching the clock and I was getting more and more upset. - b Two past actions happening at the same time. (Past Continuous + Past Continuous)
2 I was talking to my uncle when he scored. - c An action which was in progress when another action happened. (Past Continuous + Past Simple)
3 He gave me the money and I bought the car. - a Two finished actions in the past. (Past Simple + Past Simple)