Question 1101663
h Hundreds
t Tens
u Ones
-
{{{system(h=t+2,u>h,h+u=t+3t)}}},  "...three times greater than the tens digit."


{{{system(h+u=4t,h=t+2,u>h)}}}


{{{4t-u=t+2}}}
{{{3t-u=2}}}
{{{3t=2+u}}}
{{{t=(2+u)/3}}}
Individual digits for u which could work for this last equation:
0, no.
1, yes.
2, no.
3, no.
4, yes.
5, no.
6, no.
7, yes.
8, no.
9, no.
-
The possible TWO-DIGIT part, for the tens & ones,  _tu, might be one of:
<pre>11, 24, 37</pre>


One specified requirement,  u>h, units greater than hundreds digit.  This means possible tens&units must be from <pre>24, or, 37</pre>.


Determining the hundreds digit:
{{{h+u=4t}}}
{{{h=4t-u}}}
-
If _24, then {{{h=4*2-4=8-4=4}}}.
If _37, then {{{h=4*3-7=12-7=5}}}.


Specified requirement, {{{u>h}}}.
_24, {{{4>4}}}?  No.
_37, {{{7>5}}}? YES.......{{{highlight_green(h=5)}}}


---------------------------------
---------------------------------
The mystery number:  537
---------------------------------
---------------------------------