At a meeting, 15 lunches are prepared for 15 people, but 5 more people arrive. What portion will each one get?

Since 5 more people arrived at the meeting, there will be a total of 20 people who will share the food for lunch. Now, find the portion of food each one will get, denoted as p. In fraction: $$ p=\frac{15}{20}=\frac{3}{4} $$ In percentage: $$ p=\frac{15}{20}\times100\%=75\% $$