Ron draws 16 cards from a deck of 52 cards. the deck is made up of cards of four different colors-red, blue, yellow and green. how many of the cards drawn can ron expect to be green

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?