(Variable-Length Argument List: Calculating Products) Write a program that calculates theproduct of a series of integers that are passed to function product using a variable-length argumentlist. Test your function with several calls, each with a different number of arguments.

(Replace strings) Write the following function that replaces the occurrence of a substring old_substring with a new substring new_substring in the string s. The function returns true if string s is changed, and otherwise, it returns false. bool replace_strings (string& s, const string& old_string, const string& new_string) Write a test program that prompts the user to enter three strings, i.e., s, old string, and new_string, and display the replaced string.

(Rounding Numbers) Function floor can be used to round a number to a specific decimal place. The statementy = floor(x * 10 + 0.5) / 10;rounds x to the tenths position (the first position to the right of the decimal point). The statementy                                        = floor(x * 100 + 0.5) / 100;rounds x to the hundredths position (the second position to the right of the decimal point). Write a program that defines fourfunctions to round a number x in various ways:A. roundToInteger(number)B. roundToTenths(number)C. roundToHundredths(number)D. roundToThousandths(number)For each value read, your program should print the original value, the number rounded to the nearest integer, the number rounded to the nearest tenth, the number rounded to the nearest hundredth and the number rounded to the nearest thousandth.

(Perfect Numbers) An integer is said to be a perfect number if the sum of its divisors, including 1 (but not the number itself), is equal to the number. For example, 6 is a perfect number, because   6=1+2+3. Write a functionisPerfect that determines whether parameter number is a perfect number. Use this function in a program that determines and prints all the perfect numbers between 1 and 1000. Print the divisors of each perfect number to confirm that the number is indeed perfect. Challenge the power of your computer by testing numbers much larger than 1000.

(Check test scores) The answers to a true-false test are as follows: T T F F T. Given a two-dimensional answer array, in which each row corresponds to the answers provided on one test, write a function that accepts the two-dimensional array and number of tests as parameters and returns a one-dimensional array containing the grades for each test. (Each question is worth 5 points so that the maximum possible grade is 25.) Test your function with the following data: int score = 0;

(Rounding Numbers) Function floor may be used to round a number to a specific decimalplace. The statementy = floor(x * 10 + .5) / 10;rounds x to the tenths position (the first position to the right of the decimal point). The statementy = floor(x * 100 + .5) / 100;rounds x to the hundredths position (the second position to the right of the decimal point). Writea program that defines four functions to round a number x in various waysa) roundToInteger(number)b) roundToTenths(number)c) roundToHundreths(number)d) roundToThousandths(number)For each value read, your program should print the original value, the number rounded to thenearest integer, the number rounded to the nearest tenth, the number rounded to the nearest hundredth, and the number rounded to the nearest thousandth.

(Use Python) Use the Design Recipe to define a function called  black_jack  which consumes to 2 int values greater than 0.  Return whichever value is nearest to 21 without going over. Return 0 if they both go over. Include a docstring! For example: Test Result print(black_jack(19, 21)) 21 print(blackjack(21, 19)) 21 print(black_jack(19, 22)) 19   Write three  assert_equal statements to test your function.

(Use python):The instructor of a lower division statistics class has assigned you a task: make a function that takes in a student’s score on a scale from 0 to 100 and assigns a letter grade based on the following grade boundaries.

4. (Prime Numbers) An integer is said to be prime if it is divisible by only 1 and itself. For example, 2, 3, 5 and 7 are prime, but 4, 6, 8 and 9 are not. Write a function called isPrime that receives an integer and determines whether the integer is prime or not. Write a test program that uses isPrime to determine and prints all the prime numbers between 1 and 1000. Display 10 numbers per line.