Question 1092009
Let {{{ x }}} = her score on the 6th test
Let {{{ S }}} = the sum of her first 5 test scores
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{{{ S/5 = 88 }}}
{{{ S = 440 }}}
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Now I can say:
{{{ ( S + x ) / 6 = 90 }}}
{{{ ( 440 + x ) / 6 = 90 }}}
{{{ 440 + x = 540 }}}
{{{ x = 100 }}}
She must score 100 on her 6th test in
order to average 90