Hi, I think what you need to do is multiply 21 x 4 x 1/3. If you need help multiplying there’s a helpful website called Calculator Soup that is very helpful.
Answer:

Step-by-step explanation:
Use KCF method for fraction division.
- Keep the first fraction.
- Change the division operation to multiplication.
- Flip the second fraction.


Answer:
Answer: 55
Step-by-step explanation:
Answer:
Option A is correct that is 
Step-by-step explanation:
We have been given a formula 

We will put values of n in
when n=2 we get
when n=3
Therefore, Option A is correct that is 
Answer:
3
Step-by-step explanation: