so, since she weights 6 times more on earth, say for every lb on the moon is 6lbs on earth then.
now, if 1lb on the moon is 6lbs on earth, how much is 90 earth lbs on the moon?
[tex]\bf \begin{array}{ccll}
moon&earth\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
1&6\\
m&90
\end{array}\implies \cfrac{1}{m}=\cfrac{6}{90}\implies \cfrac{1\cdot 90}{6}=m[/tex]
