Tomas works as an underwater photographer. He starts at a position that is 17 feet below sea level. He rises 6 feet, then descends 15 feet to take a photo of a coral reef. Enter an expression to find his position relative to sea level when he took the photo and then evaluate the expression. An expression for Tomas's position is
Evaluate the expression:

Tomas took the photo at
feet below sea level.

Three coins are flipped. what is the probability that there will be at least two tails?

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?

What will the graph look like for a system of equations that has no solution? a. the lines will be perpendicular. b. the lines will cross at one point. c. both equations will form the same line. d. the lines will be parallel.