Question 1059512
Let {{{ a }}} = Amy's age now
Let {{{ b }}} = Phil's age now
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The difference in their ages will
ALWAYS be {{{ 24 }}} yrs
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(1) {{{ b = a + 24 }}}
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Note that {{{ 3a = a + 2a }}}
If I add {{{ 2a }}} to Amy's age, I
must add it to Phil's, so this
is what I get:
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(2) {{{ b + 2a = 3*( a + 2a ) }}}
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(2) {{{ b + 2a = 9a }}}
(2) {{{ b = 7a }}}
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By substitution:
(1) {{{ 7a = a + 24 }}}
(1) {{{ 6a = 24 }}}
(1) {{{ a = 4 }}}
and
(1) {{{ b = a + 24 }}}
(1) {{{ b = 4 + 24 }}}
(1) {{{ b = 28 }}}
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Phil is 28 now
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check:
When Amy is 3 times as old as she is today, or
when she is {{{ 3*4 = 12 }}}
Phil will be {{{ 12 + 24 = 36 }}}
and {{{ 36 = 3*12 }}}
OK