If 0° < θ< 90°, θ is a/an what angle?

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)

You give a $4 tip for a meal that cost $22. approximately what percent of the bill was your tip?

Having a hard time understanding this question (see attachment).