What is the ratio 780 to 220 simplified?

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Solve for x and y a x= 13.3 y= 16.7 b x= 23.3 y= 12.5 c x= 7.5 y= 16.7 d x=7.5 y= 12.5

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =