Abing contains 3 red and 4 green balls. 2 balls are chosen at random, without replacement. let the random variable x be the number of aren balls chosen.
construct a probability distribution for table x.

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?