There will be two cases here ( Basically it is a problem of inclusion and exclusion principle
1. when both of them are coming :
So we have 8 people out of which 2 have already been chosen so our choice reduces to choosing 6 people out of 3 people so 6C3
2. When both of them are not coming :
So we have to choose 5 people out of 6 people so 6c5
Hence the total number of ways are 6C3 + 6C5