Can you guys pls explain how you do this? explain the steps pls

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

Kayla and alberto are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. kayla sold 3 small boxes of grapefruit and 1 large box of grapefruit for a total of $65. alberto sold 1 small box of grapefruit and 1 large box of grapefruit for a total of $55. what is the cost each of one small box of grapefruit and one large box of grapefruit?

If f(x) and g(x) are inverse functions of each other, which of the following shows the graph of f(g(x)