Question 773229
( sum of all 6 ages ) / 6 = 30
( sum of all 6 ages + age of new person ) / 7 = 38 }}}
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sum of all 6 ages = 6*30
sum of all 6 ages = 180
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( sum of all 6 ages + age of new person ) / 7 = 38
( 180 + age of new person ) / 7 = 38 
( 180 + age of new person )  = 7*38
age of new person = 7*38 - 180 
age of new person = 266 - 180
age of new person = 86 
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check answer:
{{{ ( 180 + 86 ) / 7 = 38 }}}
{{{ 180 + 86 = 266 }}}
{{{ 266 = 266 }}}
OK