What is the index of the last position in an array that contains 10 items?

Tablets, abacuses, and manual tables

a. are no longer used, because of the proliferation of calculators and computers. b. are examples of aids to manual calculating. c. were developed in Western Europe in the late Middle Ages. d. replaced Hindu-Arabic numerals as the preferred way to do calculations. e. All of the above.

Repeat Programming Project 18 from Chapter 4, but use a method that displays a circular disk as a subtask.

This application draws a bullseye. If the circle-drawing method (suggested in the hint) takes a GraphicsContext object, center x- and y-coordinates, and a Color object as parameters, then both the paint method and the circle-drawing method are quite simple and easy to write.