Question 860260
percent means " per one hundred "
{{{ 9/45 }}} is the FRACTION of the 
cards that were yellow
{{{ 9/45 = 1/5 }}}
{{{ 1/5 = 2/10 }}} is the DECIMAL FRACTION
of the cards that were yellow
{{{ ( 2/10 )*100 = 20 }}} is the PERCENT
of the cards that were yellow
So, 20% is the answer