Question 550056
Let {{{a}}} = tens digit
Let {{{b}}} = units digit
The value of the number is
{{{ 10a + b }}}
given:
{{{ 10a + b = 3*( a + b ) }}}
{{{ 10a + b = 3a + 3b }}}
{{{ 7a = 2b }}}
The only way this can be true
and {{{a}}} and {{{b}}} are both 
single digit whole numbers is
{{{ a = 2 }}}
{{{ b = 7 }}}
The number is 27
check answer:
{{{ 10a + b = 3*( a + b ) }}}
{{{ 10*2 + 7 = 3*( 2 + 7 ) }}}
{{{ 20 + 7 = 3*9 }}}
{{{ 27 = 27 }}}
OK