Need answer interval notation (domain) thnx

Colby and jaquan are growing bacteria in an experiment in a laboratory. colby starts with 50 bacteria in his culture and the number of bacteria doubles every 2 hours. jaquan starts with 80 of a different type of bacteria that doubles every 3 hours. let x equal number of days. colbys experiment follows the model: a.) y=50*2^x b.) y=50*2^8x c.) y=50*2^12x jaquans experiment follows the model: a.)80*2^x b.)80*2^8x c.)80*2^12x

240 seventh graders and two-thirds of the students participate in after-school activities how many students participate in after-school activities

Roderick wants to draw a circle for which the numerical value of the circumference is greater than the value of the area.which lengths could he use for the radius? check all that apply