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

Answer:

10.67

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;

$k=\frac{P}{QR}=\frac{6}{3\times12}=\frac{6}{36}=\frac{1}{6}$

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

$P=\frac{1}{6}\times4\times16=\frac{64}{6}=10.67$