C++ program how to check a math problem?

The part of my program I am working on is supposed to give the user random multiplication problems, the user gives an answer, then the program says correct or incorrect. 2 Questions


1. How do I check to get the real answer?


2. If it is incorrect I have to let them retry the same problem up to 3 times. Since I am using a random # generator in a separate function I don't know how to make the exact same problem keep coming up.


This is what I have so far but I get an error


non-lvalue in assignment


what does this mean?





for(i=1;i%26lt;=PROBLEMS;i++)


{


num1=randIntBetween(minNum, maxNum);


num2=randIntBetween(2, maxNum);


cout%26lt;%26lt;i%26lt;%26lt;")"%26lt;%26lt;num1%26lt;%26lt;"x"%26lt;%26lt;num2%26lt;%26lt;"=";


cin%26gt;%26gt;stuAnswer;


num1 * num2 = trueAnswer;


if (stuAnswer == trueAnswer)


{cout%26lt;%26lt;"Correct!";


numRight++;


}

C++ program how to check a math problem?
First, change num1 * num2 = trueAnswer;





to:





trueAnswer = num1 * num2;