Question

P varies jointly with Q and R,and P=6 when Q=3 and R=12.Find P Q=4 and R=16

Answer 1

10.67

Step-by-step explanation:

We're told that P varies jointly as Q and R, this can be represented as shown below;

`\begin{gathered} P\propto QR \\ P=\text{kQR} \end{gathered}`

where k = constant of proportionality

Given P = 6, Q = 3 and R = 12, let's go ahead and solve for k;

`k=(P)/(QR)=(6)/(3*12)=(6)/(36)=(1)/(6)`

Knowing k = 1/6, let's solve for P when Q = 4 and R = 16;

`P=(1)/(6)*4*16=(64)/(6)=10.67`