Answer:
Constant of variation is: 15
Step-by-step explanation:
r varies directly with p and inversely with the product of s and t
It can be written as:
r ∝ p/st
When the proportionality symbol is removed, a constant is introduced which is called constant of variation
So
[tex]r = \frac{kp}{st}[/tex]
Putting p = 12, t= 2, and s = 5 and r = 18
[tex]18 = \frac{k * 12}{2*5}\\18 = \frac{12k}{10}\\12k = 18*10\\12k = 180\\\frac{12k}{12} = \frac{180}{12}\\k = 15[/tex]
Hence,
Constant of variation is: 15
