The time period of a pendulum is 0.5 s. No of oscillations of the pendulum is 20. Find the time taken to complete 20 oscillations (with explanation pls)

What is the slope of the line shown below?

Negative 5 1/12 + negative 4 1/4 + 6 3/4

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?