Question

How many subsets of four elements each exist in a set of seven elements?

Answer 1

i will guess this is the same as asking how many ways can you choose 4 from a set of 7 and the answer is called "7 choose 4" and written as
\[\dbinom{7}{4}=\frac{7\times 6\times 5}{3\times 2}\]

Answer 2

cancel first, multiply last you get \(7\times 5=35\)

Answer 3

thanks!

Answer 4

yw