(Average a Sequence of Integers) Write a program that calculates and prints the average ofseveral integers. Assume the last value read with scanf is the sentinel 9999. A typical input sequencemight be10 8 11 7 9 9999indicating that the average of all the values preceding 9999 is to be calculated

(Financials: currency exchange) Write a program that prompts the user to enter the exchange rate from currency in U.S. dollars to Rupees PKR. Prompt the user to enter 0 to convert from U.S. dollars to Rupees PKR and 1 to convert from Rupees PKR and U.S. dollars. Prompt the user to enter the amount in U.S. dollars or Rupees PKR to convert it to Rupees PKR or U.S. dollars, respectively. Use c++ program.

(Phone key pads) The international standard letter/number mapping found on the telephone is shown below: 100 2 abc 3 def 4 ghi 5 ikl 6mno 7pgrs 8 tuv 9wxyz Write a program that prompts the user to enter a letter and displays its correspond- ing number.

(Financial: credit card number validation) Credit card numbers follow certain pat- terns. A credit card number must have between 13 and 16 digits. It must start with: 4 for Visa cards 5 for Master cards 37 for American Express cards 6 for Discover cards In 1954, Hans Luhn of IBM proposed an algorithm for validating credit card numbers. The algorithm is useful to determine whether a card number is entered correctly or whether a credit card is scanned correctly by a scanner. Credit card numbers are generated following this validity check, commonly known as the Luhn check or the Mod 10 check, which can be described as follows (for illustra- tion, consider the card number 4388576018402626): 1. Double every second digit from right to left. If doubling of a digit results in a two-digit number, add up the two digits to get a single-digit number. 4388576018402626 → 2 * 2 = 4 → 2 * 2 = 4 → 4 * 2 = 8 → 1 * 2 = 2 6 * 2 = 12 (1+ 2 = 3) → 5 * 2 = 10 (1+ 0 = 1) → 8 * 2 = 16 (1 + 6 = 7) → 4 * 2 = 8

5. (Algebra: solve 2 X 2 linear equations) You can use Cramer's rule to solve the following 2 X 2 system of linear equation: ax + by = e cx + dy = f ● x = ed - bf bc ad y = af - ec ad bc - Write a program that prompts the user to enter a, b, c, d, e, and f and display the result. If ad- bc is 0, report that The equation has no solution. Enter a, b, c, d, e, f: 9.0, 4.0, 3.0, -5.0, -6.0, -21.0 Enter x is -2.0 and y is 3.0 Enter a, b, c, d, e, f: 1.0, 2.0, 2.0, 4.0, 4.0, 5.0 Enter The equation has no solution

(Sort three numbers) Write the following function to display three numbers in increasing order: def displaySortedNumbers(num1, num2, num3): Write a test program that prompts the user to enter three numbers and invokes the function to display them in increasing order. Here are some sample runs:

(Count the letters in a string) Write a function that counts the number of letters in a string using the following header: def countLetters(s) : Write a test program that prompts the user to enter a string and displays the number of letters in the string. the answer should be in python.

(Sort three integers) Write a program that prompts the user to enter three integers and displays them increasing order.

(Summing Integers) Write a program that uses a for statement to sum a sequence of integers. Assume that the first integer read specifies the number of values remaining to be entered. Your program should read only one value per input statement. A typical input sequence might be5 100 200 300 400 500 where the 5 indicates that the subsequent 5 values are to be summed.