A certain colony of bacteria began with 60 cells, and the population tripled every 20 minutes. What was the population of the colony after 3 hours? 45,178
55,216
43,740
59,144

Consider u = {x|x is a negative real number}which is an empty set? o {x|x eu and x has a negative cube root}o {x|x eu and x has a negative square root}{x|x eu and x is equal to the product of a positive number and -1}{x|x eu and x is equal to the sum of one negative and one positive number?