SOMEONE ANSWER AND EXPLAIN ILL MARK BRAINLIEST!!!!!!!!!

Answer:
For question 10, the next 3 sequences are 21, 34, and 55.
Step-by-step explanation: The Fibonacci sequence is where you take the last 2 number of the sequence and add the together to get the next number.
I hope this helps.
Answer:
Number 9 is, 21 handshakes
Number 10 part a is 21, 34, and 55.
Not sure on part b
Step-by-step explanation: