Answer:
I believe the number of terms are 10
Step-by-step explanation:
Answer: He can completely decorate 11 cars
Explanation: since he puts 2 snowflakes on each of the 4 windows on one car, in total Jack uses 8 snowflakes per car. If he makes 90 snowflakes, 90 divided by 8 gives you the amount of cars he can decorate. 90/8 = 11.25, but since you can’t have .25 cars the answer is 11.
The question is an illustration of arithmetic sequence.
<em>The number of conversation for 19 people is 171</em>
<u />
<u>(a) 9 people</u>

9 represents the number of people
8 represents the number of conversation each person had
2 represents the number of people having a conversation at once (i.e 2 people at once)
<u>(b) 19 people</u>
We have:

The number of conversation is:

So, we have:




Hence, the number of conversation for 19 people is 171
Read more about arithmetic sequence at:
brainly.com/question/18109692