The mean radius of the Earth is 6378 km, to the nearest km. Assume that the Earth is a sphere. Find upper and lower bounds for: a) the surface area of the Earth in km²
b) the volume of the Earth in km³

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults. how many students and adults went if the ticket charge was $42.75

Which situation can be modeled by the inequality 5 + 10w ≥ 45? a. you start with $5 and save $10 a week until you have at least $45. b. you start with 5 baseball cards and purchase 10 cards every week until you have at most 45 cards. c. you start with 5 water bottles and purchases cases of 10 water bottles each until you have a total of 45 water bottles. d. you spend $5 plus $10 per week until you have less than $45.

Select the conic section that represents the equation. 3x2 + 3y2 -2x + 4 = 0