Barry put all of the tiles shown below into a bag, then randomly pulled out one round one and one square one. What is the probability that Barry drew two red tiles? Round tile: 21 blue, 5 green, 7 yellow, 3 red. Square tiles: 12 blue, 14 yellow, 9 red, 6 purple, 3 brown, 4 white, 12 green. a. 9/1,024 b. 1/15 c. 1/80 d. 3/80

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?