Question

sara is packing for a trip. she has 16 pairs of shoes. if she has room to pack 5 pairs, how many ways can she choose which shoes to take

Answer 1

It i given that n = 16, which is the total number of shoes and r = 5.

The number of ways she can choose which shoes to take is determined by combination.

$^nC_r=\frac{n!}{r!(n-r)!}$

Substitute the values,

$^{16}C_5=\frac{16!}{5!11!}=\frac{16\times15\times14\times13\times12\times11!}{5\times4\times3\times2\times1\times11!}$

Hence the answer is 4368. The number of ways she