On a random Friday in the fall, 95% of students were present at school. If there are a total of 420 students enrolled, then how many students were present that day​

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?

Walking at a constant rate of 8 kilometers per hour, juan can cross a bridge in 6 minutes. what is the length of the bridge in meters?

On which number line are -3 and its opposite shown