Question

At the banquet, the ratio of the number of girls is 5 : 3. Halfway through the banquet, 20 boys leave and the ratio becomes 5:4. How many girls are at the banquet?

Answer 1

$\frac{5}{8}x-20=\frac{5}{9}x\\-20=\frac{-5}{72}x\\x=288\\\frac{3}{8}(288)\\108$

108 girls