Four fifths of senior class went to prom. if 324 seniors went to prom, how many are there in the senior class

Need on this one asap im almost done with this subject

The volume of the sun is approximately 1 × 10^18 cu km, while the volume of jupiter is approximately 1 × 10^15 cu km. which of the following is true? a. the volume of jupiter is approximately one thousand times the volume of the sun. b. the volume of jupiter is approximately one hundred times the volume of the sun. c. the volume of the sun is approximately one thousand times the volume of jupiter. d. the volume of the sun is approximately one hundred times the volume of jupiter.

What fraction is equivalent to 0.46464646··· a. 46⁄99 b. 46⁄999 c. 46⁄100 d. 23⁄50