In a residential school of Dehradun the Chess club has 4 more members than the Carrom club. What number should replace the ?

Carrom circle $=19+6+5+3=33$, so the Chess circle has $33+4=37$ members. Chess circle $=?+6+7+3$, so $?=37-16=21$. 24 forgets the centre 3, 37 is the whole Chess circle, and 13 reads the clue as 4 fewer.