# Creating random problems by using rand option

I would like to generate random questions based on a random integer input. I have tried he code from a site online and tweaked it so that it generates more than one random problem but evidently it does not generate random problems. In the enumerate, the same problem appears. Any insight into the matter will be highly appreciated.

\documentclass[letterpaper]{article}
\usepackage{amsmath,amssymb,enumitem}
\usepackage{lcg,calc}
\usepackage{tikz}
\reinitrand[first=1, last=10, counter=num]  \rand
\reinitrand[first=2, last=20, counter=deno] \rand
\reinitrand[first=2, last=5, counter=coeff] \rand
\setcounter{num}{\value{coeff}*\value{num}}
\setcounter{deno}{\value{coeff}*\value{deno}}
\newcommand{\fracquestion}[1]{%
\foreach \i in {1,...,#1}
{
\item $\dfrac{\thenum}{\thedeno}$
}}
\begin{document}
\begin{enumerate}
\fracquestion{5}
\end{enumerate}
\end{document}


If you move the random number generating code within the \foreach and ajdust the seed values you get:

\documentclass[letterpaper]{article}
\usepackage{amsmath,amssymb,enumitem}
\usepackage{lcg,calc}
\usepackage{tikz}

\newcommand{\fracquestion}[1]{%
\foreach \i in {1,...,#1}{%
\reinitrand[first=\i, last=10, counter=num]  \rand
\reinitrand[first=\i, last=20, counter=deno] \rand
\reinitrand[first=\i, last=5, counter=coeff] \rand
\setcounter{num}{\value{coeff}*\value{num}}
\setcounter{deno}{\value{coeff}*\value{deno}}
\item $\dfrac{\thenum}{\thedeno}$
}
}
\begin{document}
\begin{enumerate}
\fracquestion{5}
\end{enumerate}
\end{document}


Alternatively you could just use the random number generation capability already built into PGF (which is included with tikz):

\documentclass{article}
\usepackage{amsmath}
\usepackage{enumitem}
\usepackage{tikz}

\newcommand{\fracquestion}[1]{%
\foreach \i in {1,...,#1}{%
\item $\dfrac{\pgfmathparse{random(10)}\pgfmathresult}{\pgfmathparse{random(20)}\pgfmathresult}$%
}
}
\begin{document}
\begin{enumerate}
\fracquestion{5}
\end{enumerate}
\end{document}
\begin{document}

• Thank you. I will try to apply the same principle to simple quadratic equations to try to generate problems with equal roots, distinct roots and imaginary roots. – azetina Jan 23 '12 at 19:01
• I am looking at random math problems. How can I get only the quadratic equations and using the same principle as above; that is, with random problems generated? – azetina Jan 24 '12 at 14:57
• Huh??? Not sure exactly what you want to do. A quadratic equation just needs three random numbers \a, \b, \c, and then $\a x^2 + \b x + \c$ would be a randomly generated quadratic equation. I suspect that you are looking for something else.. If it is not related to thrust of this question (i.e., how to generate random numbers) it should probably be posted as a new question. – Peter Grill Jan 24 '12 at 15:59
• @PeterGrillOk I will try to post as a new question. – azetina Jan 24 '12 at 16:04
• OK, figured. This line was missing from the preamble \pgfmathsetseed{\number\pdfrandomseed}. – Atcold Sep 6 '16 at 13:13