http://www.math.duke.edu/~rtd/PTE/PTE4_1.pdf [2]
http://www.cpm.org/pdfs/state_supplements/probability.pdf [3]
https://www.math.ust.hk/~maykwok/courses/ma246/04_05/04MA246Ex1_Bas.pdf [4]
http://www.cimt.plymouth.ac.uk/projects/mepres/book8/bk8_10.pdf [5]
http://www.sjsu.edu/faculty/gerstman/StatPrimer/probability.pdf [6]
http://www.maths.qmul.ac.uk/~pjc/notes/prob.pdf [7]
https://www.ma.utexas.edu/users/gordanz/notes/solved_problems.pdf [8]
https://www.math.ucdavis.edu/~gravner/MAT135A/resources/lecturenotes.pdf [9]
Links
[1] https://www.hootsgo.org/?q=node/6728
[2] http://www.math.duke.edu/~rtd/PTE/PTE4_1.pdf
[3] http://www.cpm.org/pdfs/state_supplements/probability.pdf
[4] https://www.math.ust.hk/~maykwok/courses/ma246/04_05/04MA246Ex1_Bas.pdf
[5] http://www.cimt.plymouth.ac.uk/projects/mepres/book8/bk8_10.pdf
[6] http://www.sjsu.edu/faculty/gerstman/StatPrimer/probability.pdf
[7] http://www.maths.qmul.ac.uk/~pjc/notes/prob.pdf
[8] https://www.ma.utexas.edu/users/gordanz/notes/solved_problems.pdf
[9] https://www.math.ucdavis.edu/~gravner/MAT135A/resources/lecturenotes.pdf