Question

1. Anita plans to give her husband 4 shirts for his birthday. She narrows the search to 4 shirts from a selection of 15 shirts at Dillon's Store or 4 from a selection of 20 shirts at The Men's Shop. In how many ways can she select the shirts

Answer 1

Answer:

6210

Step-by-step explanation:

This is simple problem of section of few things from  a lot.

$A_{1}$: selection of 4 shirts from 15 shirts

$A_{2}$: selection of 4 shirts from 20 shirts

$A_{1}$ =   $\binom{15}{4}= \frac{15!}{4!\times11!}$

=1365

$A_{2}$ =   $\binom{20}{4}= \frac{20!}{4!\times16!}$

=4845

so the number of ways in which she can select shirts

= 1365+4845= 6210