Convert the following decimal below into a rational number 0.1

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Could someone with number 1 and 2