A square has an area of 144in2

Pls! does anybody know a shortcut for answering these types of questions in the future?

Determine the number of outcomes in the event. decide whether the event is a simple event or not. upper a computer is used to select randomly a number between 1 and 9 comma inclusive. event upper b is selecting a number greater than 4. event upper b has nothing outcome(s). is the event a simple event? (yes or no) because event upper b has (fewer than, exactly, more than) one outcome.

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*