A professor teaches a very small class with only 4 students. One day, when returning a test, the professor simply shuffles the tests and hands each student one of the tests at random.
(Write all answers as fractions, not decimals) What is the probability all 4 students receive the correct test?
What is the probability that no one receives the correct test?|
What is the probability that one or more students receive the correct test?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)

The area (a) of a circle with a radius of r is given by the formula and its diameter (d) is given by d=2r. arrange the equations in the correct sequence to rewrite the formula for diameter in terms of the area of the circle.