Answer:
[tex]\frac{f}{3}[/tex]
Step-by-step explanation:
Given,
There are 3 feet in a yard
That is, 1 yard = 3 feet,
⇒ 1 feet = [tex]\frac{1}{3}[/tex] yard,
So, the number of yards in f feet = f × number of yards in 1 feet
[tex]=f\times \frac{1}{3}[/tex]
[tex]=\frac{f}{3}[/tex]
Which is the required expression.