Assume your friend just took an exam made up of 20 true/false questions. Further assume that your friend had no knowledge relevant to the questions, and consequently just guessed the answer to each question. What is the probability he will get a B, if the B range is 80-89%?

Why do we refer to the characteristics of children's thinking between the ages of 7 and 12 as "concrete?"

a. Because they are unable to change the ways in which they think b. Because their thinking has to do with tangible objects, not abstract concepts c. Because they refuse to listen to parents and teachers d. Because they believe that theirs is the only point of view of the world.

Emilio wants to play a prank on his friend, so he buys an air-horn and sneaks up behind his buddy. He presses the button, and a deafening blast of noise comes out of the horn, causing his friend to jump straight out of his chair. The horn that Emilio used seems to have

A. a low frequency. B. a short wavelength. C. a very high amplitude. D. no timbre.