While Loop Not Counting Correctly

I've been learning programming in python for the last two weeks and it's going great so far. But now I'm stuck and can't seem to find an answer. I found a really weird behaviour of

Solution 1:

It's floating point arythmetic. Output in console for python 3.6

0
0.2
0.4
0.6000000000000001
0.8
1.0
1.2
1.4
1.5999999999999999
1.7999999999999998
1.9999999999999998