Question

How many subsets of at least four elements does a set of seven elements have?

Answer 1

7C4 +7C5 + 7C6 +7C7

Answer 2

use calculator

Answer 3

for sure.

Answer 4

thank you again elecengineer

Answer 5

or not.
1 with 7 elements
7 with 6 elements

\[\dbinom{7}{5}=\frac{7\times 6}{2}=21\] with 5 elements and
\[\dbinom{7}{4}=\frac{7\times 6\times 5}{3\times 2}=35\] for 4 elements

Answer 6

\[1+7+21+35=64\]

Answer 7

thank you satellite!