The question is an illustration of permutation and combinations.
- The number of ways she can choose 4 out of the 7 paintings is 35
- The number of ways she can arrange 4 out of the 7 paintings is 840
The given parameters are:


<u>(a) Choose 4 of 7 paintings</u>
Choosing 4 of 7 paintings implies combination.
So, we have:

Substitute values for n and r


Expand


Hence, the number of ways she can choose 4 out of the 7 paintings is 35
<u>(b) Arrange 4 of 7 paintings</u>
Arranging 4 of 7 paintings implies permutation.
So, we have:

Substitute values for n and r


Expand


Hence, the number of ways she can arrange 4 out of the 7 paintings is 840
Read more about permutation and combinations at:
brainly.com/question/15301090
Answer:
1/3
Step-by-step explanation:
2/6 means that 2 out of the 6 tills have comfy seats. 2/6 simplified is 1/3