Question 976087
Let {{{ a }}} = Ade's age now
Let {{{ b }}} = Femi's age now
Let {{{ c }}} = Funmi's age now
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(1) {{{ a + b + c = 28 }}}
(2) {{{ a = b + 1 }}}
(3) {{{ b = c + 12 }}}
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(3) {{{ c = b - 12 }}}
Substitute (2) and (3) into (1)
(1) {{{ b + 1 + b + b - 12 = 28 }}}
(1) {{{ 3b - 11 = 28 }}}
(1) {{{ 3b = 39 }}}
(1) {{{ b = 13 }}}
and
(2) {{{ a = 13 + 1 }}}
(2) {{{ a = 14 }}}
and
(3) {{{ c = 13 - 12 }}}
(3) {{{ c = 1 }}}
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Ade is 14
Femi is 13
Funmi is 1
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check:
(1) {{{ a + b + c = 28 }}}
(1) {{{ 14 + 13 + 1 = 28 }}}
(1) {{{ 28 = 28 }}}
OK