You randomly select 2 marbles from a mug containing 5 blue marbles, 4 red marbles, and 3 white marbles. How many times greater is the probability of selecting 2 blue marbles when you replace the first marble before selecting the second marble than when you do not replace the first marble before selecting the second marble? Express your answer as a fraction.

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?

The interior angles formed by the side of a hexagon have measures of them up to 720° what is the measure of angle a

Evaluate 8j -k+148j−k+14 when j=0.25j=0.25 and k=1k=1.