7 Before a certain type of book is published it is checked for errors, which are then corrected. For costing purposes each error is classified as either minor or major. The numbers of minor and major errors in a book are modelled by the independent distributions \(\mathrm { N } ( 380,140 )\) and \(\mathrm { N } ( 210,80 )\) respectively. You should assume that no continuity corrections are needed when using these models. A book of this type is chosen at random.

1. Find the probability that the number of minor errors is at least 200 more than the number of major errors.
   The costs of correcting a minor error and a major error are 20 cents and 50 cents respectively.
2. Find the probability that the total cost of correcting the errors in the book is less than \(
   ) 190$.
   If you use the following lined page to complete the answer(s) to any question(s), the question number(s) must be clearly shown.