Sagot :
[tex]\begin{array}{ccc}100\%&-&50\ pts\\\\84\%&-&x\ pts\end{array}\ \ \ |cross\ multiply\\\\100x=50\cdot84\ \ \ \ |divide\ both\ sides\ by\ 100\\\\x=\frac{50\cdot84}{100}\\\\x=\frac{1\cdot84}{2}\\\\\boxed{x=42\ (pts)}[/tex]