Mssing probability from the line

[Genie134]

How can I solve this? I have tried to count the numbers from 0 to 100 going in 10s but the answer seems to be wrong, I've tried that method as it seems to be the correct one in exams usually so I am a bit confused :?.

 

[tkhunny]

It's very hard to say without knowing what it is that is wanted.

I this supposed to be a Uniform Distribution defined [0,1]?
Any probability masses? Maybe just one

Please show YOUR best work. You can't have NO idea.