When P varies inversely as Q, the equation is P = k * 1/Q where k is the constant of proportionality.
So we can re-write this equation as P = k/Q. Our first step is going to be to find k.
P= 12, Q =6 --> 12= k/6 . So we have to multiply 12 * 6 to find k. k = 72
Now that we know k, the equation can be re-written as P = 72/Q
When P = 8, the equation is 8 = 72/ Q. We solve by multiplying Q on both sides so
8Q = 72 and we can divide by 8 on both sides so Q = 9.