Which of the following format isn't supported by which Android.a.MIDIb.MPEGc.MP4d.AVI

All the formats mentioned (MIDI, MPEG, MP4, AVI) are supported by Android. However, the level of support can vary depending on the specific device and the version of the Android operating system it is running.

1. MIDI: Android has built-in support for playing MIDI format files.

2. MPEG: Android supports various types of MPEG files, including .mpg, .mp2, .mpeg, .mpe, .mpv, and .m4v.

3. MP4: Android has native support for this format. It's one of the most commonly used formats for video files on Android devices.

4. AVI: Android does not natively support AVI. However, there are many third-party video player apps available that can play AVI files on Android devices.

So, to answer your question, AVI is the format that isn't natively supported by Android.