Can someone help me understand how to do this?

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)

How many real-number solutions does the equation have? -4x^2 + 10x + 6 = 0 a. no solutions b. two solutions c. infinitely many solutions d. one solution

Describe the symmetry of the figure. identify lines of symmetry, if any. find the angle and the order of any rotational symmetry.