Question

a person has 6 friend in how many can he invite atleast one friend to his House find combination

Answer 1

the answer is equalto 6

Answer 2

There are 6 ways to invite any friend.
$\huge{\bold{\green{6\: ways}}}$

But

if question is

A person has 6 friends in how many ways can he invite one or more of them in party ?

6C1 +6C2+6C3+6C4+6C5+6C6=

== 6 +(6×5/2×1) +(6×5×4/3×2×1) +(6×5×4×3/4×3×2×1) +(6×5×4×3×2×1/5×4×3×2×1) +(1)

= 6 +15 +20 +15 +6 +1
=63

So Answer is

$\huge{\bold{\orange{63\: ways}}}$