Answer
$ 7\%$ of people kissing someone with colds will actually catch the cold.
Work Step by Step
Typical percentage problem:
What percent ($n$, as a decimal number) of (the base amount $y$) is $x?$
Translated:$\quad n\cdot y=x$
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Here, What percent ($n$, as a decimal number) of ($y=800$ is ($x=56$)$?$
Translated:$\quad n\cdot 800=56$
... divide with $800$
$ y=0.07\qquad$ .... convert to percent notation,
(move the decimal point two places to the right and write a percent symbol.)
$=7\%$