Question 1102620
Let {{{ a }}} = the son's age now
Let {{{ b }}} = the father's age now
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(1) {{{ b - 4 = 3*( a - 4 ) }}}
(2) {{{ ( a + 4 ) + ( b + 4 ) = 64 }}}
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(1) {{{ b - 4 = 3a - 12 }}}
(1) {{{ 3a - b = 8 }}}
and
(2) {{{ a + b + 8 = 64 }}}
(2) {{{ a + b = 56 }}}
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Add (1) and (2)
(1) {{{ 3a - b = 8 }}}
(2) {{{ a + b = 56 }}}
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{{{ 4a = 64 }}}
{{{ a = 16 }}}
and
(2) {{{ 16 + b = 56 }}}
(2) {{{ b = 40 }}}
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The father is 40 at present
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check:
(1) {{{ b - 4 = 3*( a - 4 ) }}}
(1) {{{ 40 - 4 = 3*( 16 - 4 ) }}}
(1) {{{ 36 = 3*12 }}}
(1) {{{ 36 = 36 }}}
and
(2) {{{ ( a + 4 ) + ( b + 4 ) = 64 }}}
(2) {{{ 20 + 44 = 64 }}}
(2) {{{ 64 = 64 }}}
OK