Hello. I've tried to change the syntax of the previous question I've submitted. Details:

Question variables in the problematic question:

Vx: rand([200,250,300,350,400,450,500,550,600,650,750,1150,1350,1700,2100]); /* objem roztoku NaCl v cm3*/

mx: rand_with_step(2,15,1); /* hmotnost tuheho NaCl v roztoku v g*/

vztah_c: ((1000*m)/(M*V));

MolHmot: 58.0; /* Molova hmotnost NaCl */

ta1: vztah_c;

ta2: decimalplaces(subst([m=mx,V=Vx,M=MolHmot],vztah_c),2);

ta3:mol/dm^3,true],[mol,false],[bar,false;

The student is supposed to calculate molar concentration for NaCl in its solution of V={@Vx@} cm^{3},** **which contains m={@mx@} g NaCI. Molar mass of NaCl = 58.

The inputs are:

ans1 is an algebraic input, the model answer is: ta1

ans2 is an alg. input as well, and the model answer is: ta2

ans3 is a drop-down list, and the model answer is: ta3

The response trees:

Potential response tree: prt1 Node 1: Answer test: AlgEquiv; SAns: ans1; TAns: ta1

Potential response tree: prt2 Node 1: Answer test: AlgEquiv; SAns: ans2; TAns: ta2

Potential response tree: prt3 Node 1: Answer test: UnitsAbsolute; SAns: ans3; TAns: ta3 and test options: ta3

My questions are:1.) Where is the mistake? Because when the student selects the correct answer in the drop-down list, the response says:

The answer test failed to execute correctly: please alert your teacher.

2.) Is there a way how to put two input boxes in the question right next to each other (because they always show up in other lines)? It would be convenient if the right numeric answer and its unit would be as closely put as possible. Thank you.