The lemonade stand is selling 2 types of lemonade. On the first day is the sale, the stand sold 3 strawberry lemonade and 1 original lemonade for a total of $38. The stand took in $52 on the second day selling 3 strawberry lemonade and 2 original lemonade. Fine the cost of each type of lemonade.

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?