Answer:
There are 16 ways in which Danny can mix and match all his outfits. You can determine this by multiplying. 4 x 2 x 2. Danny has 4 shirts. He can wear each with two different pants, so 4 x 2 giving 8 different shirt/pant combinations. Now each combination can be worn with two different pairs of shoes, so 8 x 2 giving 16 total combinations of shirt, pants and shoes.
Explanation:
How many outfits does that make? First he has to decide on a pair of pants and he has 4 different choices. For each of those choices he has a choice of 7 ...