The Mathh Application

/* This is an application to help someone to calculate factorials, combinations and permutations * Exit and Reset Button - use a messagebox to confirm with the user before performing the actions * Submit Button * The user can select any options - if no options are selected, provide a messagebox to inform the user there are no selections, clear the form * Only integer numbers greater than 0 are allowed in N and r. * Make sure that the listbox is empty for each submission. * Factorial - if two numbers are entered, calculate the factorial of the two numbers * Factorial N! = 1 x 2 x 3 x 4 .... x N, e.g. Factorial 4! = 1 X 2 X 3 X 4 = 24 * * This is basically using looping to multiply the number starting from 1 until you reach the last number. * Once you have the factorials, you can then use the results to calculate the permutations and combinations. * * Combination and Permutation - here you should also check that r is smaller or equal to N * Combination (N, r) = N!/(r!(N-r)!, e.g. Combination (4,2) = 4!/2!(4-2)! = 24/(2x2) = 6 * Permutation (N, r) = N!/(N-r)!, e.g. Permutation (4,2) = 4!/(4-2)! = 24/2 = 12 * * Display the outputs in the listbox */