2. Typos. (10 points) Assume a 10-page scientific journal paper has 10 typos in it. (a) If the typos are randomly distributed over the 10 pages, find the probability of having a single typo on each page. (b) If 8 of the typos are spelling errors and the other two are mathematical errors, find the probability of having 4 spelling errors and a single mathematical error on the first five pages of the paper