A: Find the number of ways of putting 5 letters in the envelope in such a way that no letter is being put in the right envelope. B. In a holiday party, each 6 attendants brings in a gift and exchanges it with someone

else in the party. Find the number of ways of exchanging so that no one gets his/her gift back.

C. If you have 7 pairs of parentheses then how many valid groups of them one can make?

D. The number of ways one can triangulate a regular polygon with 5 sides is…?

Write a function 'music_func' that takes 3 parameters -- music type, music group, vocalist -- and prints them all out as shown in the example below. in case no input is provided by the user, the function should assume these values for the parameters: "classic rock", "the beatles", "freddie mercury". for example: input: alternative rock,pearl jam,chris cornell output: the best kind of music is alternative rock the best music group is pearl jam the best lead vocalist is chris cornell note: the print statements will go inside the for example: print("the best kind of music is"

How might the success of your campaign be affected if you haven’t carefully completed all field data or if you accidentally insert the wrong merge field in the document?

Write a program that displays the following menu: geometry calculator 1. calculate the area of a circle 2. calculate the area of a rectangle 3. calculate the area of a triangle 4. quit enter your choice (1-4): if the user enters 1, the program should ask for the radius of the circle and then display its area. use the following formula: area = ď€(the square of r) use 3.14159 for ď€ and the radius of the circle for r. if the user enters 2, the program should ask for the length and width of the rectangle and then display the rectangle’s area. use the following formula: area = length * width if the user enters 3, the program should ask for the length of the triangle’s base and its height, and then display its area. use the following formula: area = base * height * .5 if the user enters 4, the program should end. input validation: display an error message if the user enters a number outside the range of 1 through 4 when selecting an item from the menu. do not accept negative values for the circle’s radius, the rectangle’s length or width, or the triangle’s base or height. note: if the user enters an improper menu choice (1-4), the program prints "the valid choices are 1 through 4. run the program again and select one of those." if the user enters a negative radius, the program prints "the radius can not be less than zero." if the user enters a negative value for height or base, the program prints "only enter positive values for base and height."