A series of waves traveling at 200m/sec are being generated by a 100 Hz source. A point at the very top of the crest of a certain wave is _______ meters from a corresponding point 3 'crests' away.

0
1.5
2.7
4
6.0
12.0
16.0
30000

I think its 4 b/c 200+200=400 and 400/100=4

V = (f)* (wavelength)

200m/s = 100hz * Wavelength

solve for wavelength then multiply by 3

dont forget to use the units for each variable like he gave us in class i.e.
frequency = vibration/time
wavelength = distance/vibration
velocity = distance/time