Carbon-11 has a half-life of about 20 minutes if we start with 200 grams how much will be left after 3 hours?

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

Acircular city park has a sidewalk directly through the middle that is 111 - feet long. if each bag of fertilizer covers 50 square feet, then determine how many bags of fertilizers the parks and recreation department needs to use to cover the circular park. ignore all the sidewalks around and through the park.

Which ordered pair is a solution to the system of linear equations? 2x + 3y= 6 –3x + 5y = 10