ATTENTION! The code above does not give complete random variables, but a slightly skewed distribution of random variables.
However, 
I have found a better solution to create two unique random variables:
1) Create three random variables (questions of the type equation), e.g. RANDOM, RANDOMTWO, RANDOMINT in this order.
2) RANDOM gets the equation:
Code:
{if(RANDOM>=1,RANDOM,rand(1,2))}
 
3) RANDOMTWO gets the equation:
Code:
{if(RANDOMTWO >=1, RANDOMTWO, rand(1,2))}
 
4) RANDOMINT gets the equation:
Code:
{RANDOMTWO=(if(RANDOMTWO==RANDOM, rand(1,2), RANDOMTWO))}
 
--- to increase uniqueness you simply repeat this formula in the equation like this:
Code:
{RANDOMTWO=(if(RANDOMTWO==RANDOM, rand(1,2), RANDOMTWO))} {RANDOMTWO=(if(RANDOMTWO==RANDOM, rand(1,2), RANDOMTWO))} {RANDOMTWO=(if(RANDOMTWO==RANDOM, rand(1,2), RANDOMTWO))} {RANDOMTWO=(if(RANDOMTWO==RANDOM, rand(1,2), RANDOMTWO))}