How many times heavier is a 16 1/2 pound rockthen a 10 1/2 pound rock

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?