106we need to select 7 out of 10 relatives and 2 out of the remaining 5 acquaintances
selection of 7 relatives out of 10 can be done in: 10C7 ways = 10!/(7!3!) = 120 ways
similarly selection of 2 guests out of remaining 5 acquaintances can be done in 5C2 ways = 5!/(2!3!) = 10 ways
so total no. of ways = 120*10 = 1200 ways
