Iam a 3 digit number. my tens digit is 5 more than my ones digit. my hundreds digit is 8 less than my tens digit. what number am i?

3 digits
tens=one+5
hundreds=tens-8 -> hundreds+8=tens=one+5

our hundreds number is not 0, because it is a 3 digit number
hundreds=tens-8>0
when is tens-8>0?
tens>8, the only option is tens=9

then you can fill this into the other equations:
hundreds=tens-8
9-8=1=hundreds

tens=one+5
9=one+5
4=one

so the complete number is 194