How much work is done in moving a charge of 3 coulomb from a point at the volts 115 to a point at 125 volts?

Oh, dude, moving a charge of 3 coulombs from 115 volts to 125 volts requires doing work equal to the change in potential energy. So, the work done would be 3 coulombs multiplied by the potential difference of 10 volts, which gives you 30 joules of work. It's like moving your friend's couch up a flight of stairs - tiring, but necessary.