15 grams of a radioactive substance decayed 11% over the course of 3 weeks. how many grams of the substance were left after the 3 weeks?

What is the common difference in the following arithmetic sequence 7,3,-1,-5

In an experiment you are to flip a two sided coin 100 times and record 55 heads up and 45 tails up determine the theoretical and experimental probability of getting a heads up in the experiment.

Vinay constructed this spinner based on the population of teachers at his school according to vinays model what is the probability that he will have a male history teacher two years in a row