Answer:
We get Q=63 when p=81
Option A is correct.
Step-by-step explanation:
We are given that
We can write it as
Where k is constant of proportionality.
We are given Q = 21 when p = 9
Using this Q = 21 when p = 9 we can find value of k
So, we get constant of proportionality k = 7
Now, Finding the value of Q when p = 81
We are given p=81, k=7, we need to find Q
Using the equation we can find value of Q.
So, we get Q=63 when p=81
Option A is correct.