The documentation to which madhan ravi pointed is a good resource. Another is the free MATLAB Onramp online course that will teach you the basics of how to work with MATLAB. I haven't gone through it myself but from the description I suspect lessons 2 through 5 will show you what you need to complete those questions.
After that, if you're looking for more problems on which to practice your MATLAB skills take a look at Cody, particularly the "Introduction to MATLAB" and "Basics on Vectors" problem groups.
