ro#4: Use an apppriate formula for
- sure to be somewhere in your class notes or textbook. In fact, all of these questions rely on your ability to translate the words into basic probaility statements and then manipulate and apply basic formulae. You are well-advised to go back and thoroughly review all this material, including working through worked examples.
In future, please don't post more than two questions in a thread. Otherwise the thread can get convoluted and difficult to follow. It is better for forum organization and better for you to get your questions answered in a more timely manner if you start new threads as necessary for remaining questions. eg. If you have five questions, post two of them in two threads and start a new thread for the remaining one etc.
And if the question has more than two parts to it, it is best to post only that question and its parts in the thread and start a new thread for other questions.