How can limit how many times an operator shows up in my maths quiz in vb?

import random

ops = ['+', '-', '*', '/']
num1 = random.randint(0,12)
num2 = random.randint(0,10)
operation = random.choice(ops)

print(num1)
print(num2)
print(operation)

maths = eval(str(num1) + operation + str(num2))

print(maths)

$(document).ready(function(){
    $('input[type="button"]').click(function(){
            //alert box feedback before generating random numbers
        var num1=parseInt($("#number1").text());
        var num2=parseInt($("#number2").text());
        var total = num1 + num2;
        var answer = parseInt($("input[type='text']").val());

        if ($("input[type='text']").val() === '') {
            alert("You have not key in any answer");
        } else if (answer === total) {
            alert("You have key in the right answer");
        } else {
            alert("You have key in the wrong answer");
        }

        //generate a random number range 1 to 9 for number 1 after clicking alert box using callback function
        $("#number1").innerHTML =
        Math.floor(Math.random() * 10);

        //generate a random number range 1 to 9 for number 2 after clicking alert box using callback function
        $("#number2").innerHTML =
        Math.floor(Math.random() * 10);
    });
});

    Dim dictionary = New Dictionary(Of String, Func(Of Double, Double, Double))() _
        From _
        { _
            {"+", Function(x, y) x + y}, _
            {"-", Function(x, y) x - y}, _
            {"*", Function(x, y) x * y}, _
            {"/", Function(x, y) x / y} _
        }

    Dim process As Func(Of String, String, String, Double) = _
        Function(op, x, y) _
            dictionary(op)(Double.Parse(x), Double.Parse(y))

    Dim operator = TextBox1.Text ' "+"
    Dim num1 = TextBox2.Text ' "5"
    Dim num2 = TextBox3.Text ' "4"
    Dim result = process(operator, num1, num2) ' 9

from random import randint 

while True:
    correct = 0

    userrange = int(input("How many questions would you like?\n"))

    difficulty = input("Choose your difficulty: beginner, intermediate or advanced?\n")

    if difficulty == "beginner":
            no = 10
    if difficulty == "intermediate":
            no = 25
    if difficulty == "advanced":
            no = 100

    qtype = input("Would you like to do addition, subtraction or multiplication?\n")    

    for i in range(userrange):  # Move the loop to start here, instead of under each if / elif
        n1 = randint(1, no)  # We can go ahead and generate our random numbers here also
        n2 = randint(1, no)
        if qtype == "addition":
            prod = n1 + n2
            lo = "plus"
        elif qtype == "subtraction":
            prod = n1 - n2
            lo = "minus"
        elif qtype == "multiplication":
            prod = n1 * n2
            lo = "times"


        ans = int(input("What's %d %s %d?"  % (n1 ,lo ,n2)))  # We also need to move the question into the loop, so that it is asked each time
        if ans == prod:
            print ("That's right -- well done.\n")
            correct = correct + 1
        else:
            print ("No, I'm afraid the answer is %d.\n" % prod)



    print ("\nI asked you %d questions.  You got %d of them right." %(userrange, correct))
    if correct >= (userrange%3)*2:
        print ("Well done!")
    elif (userrange%3) < correct < (userrange%3)*2:
        print ("You need more practice")
    else:
        print ("Please ask your maths teacher for help!")


    try_again = int(input("\nPress 1 to try again, press 0 to exit.\n "))
    if try_again == 0:
        break