Since the order in which we select the pictures does not matter, we can use combinations.

We must consider two possible cases:
1) Veronica includes 3 of her pictures
We can select 3 pictures from 5 pictures in 5C3 ways
5C3 = 10

2) Veronica includes 4 of her pictures
We can select 4 pictures from 5 pictures in 5C4 ways
5C4 = 5

ASIDE: Below, there's a video that shows you how to quickly calculate combinations (like 5C3) in your head

Total number of possibilities = 10 + 5
= 15
= D

Cheers,
Brent

RELATED VIDEO

_________________

Veronica can choose 3 photos in 5C3 = 10 ways
She can choose 4 photos in 5C4 = 5 ways

Total number of ways = 10 + 5 = 15

Answer: D

Select 3 photos from 5 OR select 4 photos from 5: 5C3 OR 5C4 = 5*4 + 5 = 15 (D)

The number of ways to select the photographs is:

5C3 + 5C4

(5 x 4 x 3)/(3 x 2) + 5

10 + 5 = 15

Answer: D
_________________

Could someone please help me understand where I'm going wrong?

1. Determined that the first part of the problem represents 3 selection options and 5 pictures, thus...
- 5 options for the first slot * 4 options for the second slot * 3 options for the third slot = 60 options if she chose to disclose 3 photos.

2. Recognize and solve second portion through the same means...
- 5 for first * 4 for second * 3 for third * 2 for fourth = 120 options if she chose to disclosure 4 photos.

3. Add both options together...
- Result is 180 choses. But obviously I'm wrong given that is not a possible answer.

I'm trying to do this first through basic enumeration techniques so that I can later apply the combination / permutation shortcuts with more confidence, but I believe there is a gap in my knowledge.

Thanks in advance!