Question 762239
Let {{{ m }}} = my age
Let {{{ b }}} = brother's age
Let {{{ s }}} = sister's age
---------------------
Note that if I give my sister 2 years, I become {{{ m - 2 }}}
and she becomes {{{ s + 2 }}}
Also, if my sister gives brother 1 year, she becomes {{{ s - 1 }}}
and he becomes {{{ b + 1 }}}
given:
(1) {{{ b = m - 2 }}}
(2) {{{ s + 2 = 2*( m - 2 ) }}}
(3) {{{ s - 1 = b + 1 }}}
-------------------
(3) {{{ b = s - 2 }}}
Plug this into (1)
(1) {{{ s - 2 = m - 2 }}}
(1) {{{ s = m }}}
Plug this into (2)
(2) {{{ m + 2 = 2*( m - 2 ) }}}
(2) {{{ m + 2 = 2m - 4 }}}
(2) {{{ m = 6 }}}
and, since
(1) {{{ s = m }}}
(1) {{{ s = 6 }}}
also,
(3) {{{ b = s - 2 }}}
(3) {{{ b = 4 }}}
--------------
check:
My brother is two years younger than me.
OK
If I gave my sister two years she would be twice my age
{{{ s + 2 = 8 }}}
{{{ m - 2 = 4 }}}
OK
if my sister gave my brother one year they would both the same age
{{{ 6 - 1 = 5 }}}
{{{ 4 + 1 = 5 }}}
OK