Abacteria culture begins with 4 bacteria which double in size every hour. how many bacteria exist in the culture after 8 hours?

128
256
1,024
8,192

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Askyscraper is 396 meters tall. at a certain time of day, it casts a shadow that is 332 meters long.at what angle is the sun above the horizon at that time?