What is 49% of 15? I'm very confused on this.

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

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)

Which of the following is true for the relation f(x)=2x^2+1