What is the probability of selecting a black card or a red card from a standard 52-card deck of cards?

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.

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.

Choose the more precise measurement. 26.4 cm or 8.39 cm