23 3-30.  The output of a NOR gate will be HIGH under which of the following conditions? 1.     When all inputs are HIGH 2.     When all inputs are LOW 3.     When one input is HIGH 4.     When one input is LOW 3-31.  What is the output Boolean expression for a NOR gate with  P , Q, and R as inputs? 1. R Q P + + 2. R Q P + + 3. R Q P + + 4. R Q P + + Figure 3E. Input signal timing diagram. IN ANSWERING QUESTIONS 3-32 THROUGH 3-34, REFER TO FIGURE 3E. 3-32.  Figure 3E represents the input signals to a NOR gate. What is the output expression? 1.     M + N 2. N M + 3. N M + 4. N M + 3-33.  At which of the following times will the output be HIGH? 1.     T₃ to T₄ 2.     T₈ to T₉ 3.     T₄ to T₆ and T₇ to T₈ 4.     T₃ to T₄ and T₈ to T₉ 3-34.  What should the output be between times T₃ and T₄? 1.     LOW 2.     HIGH Figure 3F. Logic gates. IN ANSWERING QUESTIONS 3-35 THROUGH 3-37, REFER TO FIGURE 3F. 3-35.  What is the output expression for gate D? 1. Z X + 2. XZ 3. Z X + 4. Z X +