It is given in the question that
There are 914.4 millimeters in a yard. There are 3 feet in a yard.
It means
[tex] 1yard=914.4 millimeters , 1 yard= 3 feet [/tex]
So we have
[tex] 914.4 millimeters = 3 feet [/tex]
Dividing both sides by 3
[tex] \frac{914.4}{3} millimeters = 1 feet [/tex]
[tex] 1 foot = 304.8 millimeters [/tex]
