Question

Microphone,kryboard,monitor out of these who is odd ones

Answer 1

microphone and keyboard input device where as monitor is output device

Answer 2

There are two types of hardware devices. They are Input Devices and Output Devices.  

The devices through which we can enter things into the computer are input devices such as micro phone and keyboard and Output devices are the ones through which we can get and see results such as monitor.

Thus, Microphone and keyboard are input devices and monitor is output device.