Question 1028740
Let {{{ f }}} = father's age now
Let {{{ d }}} = daughter's age now
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{{{ f = 45 }}}
{{{ f - 12 = 3*( d - 12 ) }}}
{{{ 45 - 12 = 3d - 36 }}}
{{{ 33 = 3d - 36 }}}
{{{ 11 = d - 12 }}}
{{{ d = 23 }}}
The daughter is 23 now
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check:
12 yrs ago, the father was {{{ 45 - 12 = 33 }}}
12 yrs ago the daughter was {{{ 23 - 12 = 11 }}}
33 is 3 times 11
OK
Also note that the difference in their ages
never changes:
{{{ 45 - 23 = 22 }}}
and
{{{ 33 - 11 = 22 }}}