C) There are 20 small towns in a district. A group of 3 people have to be chosen from I of these towns. For this purpose, volunteers are solicited from all 20 towns. Find the minimum number of...

! need correct and urgent

Extracted text: C) There are 20 small towns in a district. A group of 3 people have to be chosen from I of these towns. For this purpose, volunteers are solicited from all 20 towns. Find the minimum number of volunteers who must come forward.