Answer :
0.21212121212121212121...=7/33.
How did I find this out?
n=0.212121212121...
100n=21.212121212121...
100n-n=99n=21
Therefore n=21/99=7/33
How did I find this out?
n=0.212121212121...
100n=21.212121212121...
100n-n=99n=21
Therefore n=21/99=7/33