Match these examples as either random or systematic errors:

Electronic noise in the circuit of an electrical instrument

There is something wrong with the instrument or its data handling system

An instrument is wrongly used by the experimenter

Suppose you measure the mass of a ring three times using the same balance and you get slightly different values: $15\mathrm{.}46$ g $,15\mathrm{.}42g,15\mathrm{.}44g$