Can someone me with question number

Need in all of themmm only answer if you know pls

Will you chech and finish these for me, because i am stumped with them.

Awave travels at a speed of 5.2 m/s. if the distance between crests is 0.40 m, what is the frequency of the wave? use f=v/wavelength a. 13 hz b. 2.1 hz c. 0.077 hz d. 5.6 hz