Question

what is the speed of a wave that has a feequency of 45 HZ and a wavelwngth of 0.1 meters

Answer 1

according to the equation below \[v=f \lambda\]
where \[\lambda\] is 0.1 and frequency is 45 hence the v=4.5*0.1
0.45

Answer 2

And also make sure you consider units! But it looks like @rai013 put you in the right direction!

Answer 3

Those variable are common, by the way.
\(v\equiv \rm{velocity}\\f\equiv \rm{frequency}\\\lambda\equiv \rm{wavelength}\)