Question

Boar Ring gave a speech to an assembly of colleagues. After five minutes, half of the students left; 10 minutes later a third of the remaining audience left. After twenty more minutes, half of the remaining audience left, leaving only three people in the audience. How many people were in the audience at the beginning of Mr. Ring's speech? Boar Ring gave a speech to an assembly of colleagues. After five minutes, half of the students left; 10 minutes later a third of the remaining audience left. After twenty more minutes, half of the remaining audience left, leaving only three people in the audience. How many people were in the audience at the beginning of Mr. Ring's speech? @Mathematics