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I was using XeLaTeX in Texmaker without any problem. Suddenly I started getting the message:
Error: Could not start the command.
Thereafter I get the same massage all the time even for other files which worked well previously. The same files run without any problem on other machines. What could be ...

Dear Latex Community,

I need to list the choices for a multiple choice question in a row as follows:
1.What is the variance of X?
(a) 5 (b) 7 (c) 25 (d) 35

Is there a way to create this by modifying \begin{enumerate} ….. \end{enumerate} or something similar?

Thank you in advance for your help ...

Dear Latex Community,

I need to create a list of contents without dotted lines and page numbers as follows:

Contents
1 Introduction to Statistical Inference
1.1 Some Examples
2 Point Estimation
2.1 Estimator
2.2 Estimate
2.3 Notation
2.4 Accuracy and Precision
3 Estimation: Intuitive ...