Study the following information carefully and answer the question given below.
In a club of 30 people, all of them belong to at least one group - Chess, Drama and Art.6 people belong only to the Art group. 5 people belong to all three groups. 2 people have joined the Chess and the Art group but not the Drama group. 15 people belong to the Art group. 2 people have joined only the Chess group. 3 people have joined only the Drama group. 

Q:

How many people have belonged to the Chess group? 

• 1
  21
• 2
  13
• 3
  19
• 4
  20