Problem: The number of ounces of water needed to reduce 999 ounces of shaving lotion containing 50%50\%50% alcohol to a lotion containing 30%30\%30% alcohol is
Answer Choices:
A. 333
B. 444
C. 555
D. 666
E. 7 Solution:
412+x9+x=710;∴x=6\dfrac{4 \dfrac{1}{2}+x}{9+x}=\dfrac{7}{10} ; \quad \therefore x=69+x421​+x​=107​;∴x=6.