What is the total number of matches played in the tournament?

First Stage: There is two groups of 8 teams each. In each group, each team plays with every other team and hence total number of matches are ⁸c₂ = 8 × ( 7/2 ) = 28 matches So, in both the groups the total number of matches played at the first stage are 28. And hence 56 matches are played in 1^st stage
Second Stage: In this stage there are 8 teams playing in such a way that in one round 4 teams play with 4 other teams. 4 teams win and go to the next round. That is called knock out tournament.
In the 1^st round no of matches ( 8/2 ) = 4,
In the 2^nd round no of matches = ( 4/2 ) = 2,
In the third or the last round number of match = ( 2/2 ) = 1,
So , total no. of matches in 2^nd stage is 4 + 2 + 1 = 7
Hence total match in the tournament = 56 + 7 = 63