<u>Answer-</u>

<u>Solution-</u>
Here, n represents the number of months and f(n) represents the number of laptops in the store after n months.
As the store had 150 laptops in the month of January or at the beginning.
So 
Every month, 20% of the laptops were sold and 10 new laptops were stocked in the store.
As 20% of laptops were sold, so 80% were in the store.
So, after one month total number of laptops in the store,


Again after one month total number of laptops in the store,


Analyzing the pattern, the recursive function f(n) will be,

What are you asking me ? Do you have a picture I can look at ?
Answer (B) 2/3
Explanation: the multiplicative rate is the ratio of the values y(k)/y(k+1) (with k being the index). This ratio must be the same for the function to be exponential. We can take y(2)/y(1) = 4/6 = 2/3.
We can use 2/3 to verify the remaining entries:
x=3: 4*2/3 = 8/3 = y(3)
x=4: (8/3)*(2/3)=16/9=y(3)
Answer:
B
Step-by-step explanation:
First you find the amount of people at the reunion which was 80. Then you find 25% of 80. 25% of 80 is 20. The only age group with 20 people is the 20-29 year olds.