62 is 90.5% of what number?

What's the difference between: x≥0 and nonnegative integer. ?

Which value of c would make he following expression completely factored? 8x+cy

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)