Question 987307
Let {{{ d }}} = daughter's age now
Let {{{ m }}} = mother's age now
given:
(1) {{{ m = 3d }}}
(2) {{{ m + 12 = 2*( d + 12 ) }}}
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Substitute (1) into (2)
(2) {{{ 3d + 12 = 2*( d + 12 ) }}}
(2) {{{ 3d + 12 = 2d + 24 }}}
(2) {{{ d = 12 }}}
and
(1) {{{ m = 3d }}}
(1) {{{ m = 3*12 }}}
(1) {{{ m = 36 }}}
The mother is 36 now
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check:
(2) {{{ m + 12 = 2*( d + 12 ) }}}
(2) {{{ 36 + 12 = 2*( 12 + 12 ) }}}
(2) {{{ 48 = 2*24 }}}
(2) {{{ 48 = 48 }}}
OK