Question

The number of grams of water needed to reduce $9$ grams of shaving lotion containing $50$% alcohol to a lotion containing $30$% alcohol is

• A. $3$
• B. $4$
• C. $5$
• D. $6$
• E. $7$

Answer 1

Answer: (D)

$6$

$\frac{4\frac{1}{2}+x}{9+x}=\frac{7}{10};\therefore x=6$.