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Given the truth table below, answer the following question: How many intermediate result columns do we have? Select one: a. 4 b. 3 18. Using De Morgan's law, what is the equivalent of the expression F=xy ? R.J........... a. xy b. x+y c. x+y d. None of the above. 20. 4- Using Demorgan's law, what is the equivalent of the expression F=x+y ? a. xy b. x+y c. x+y d. None of the above. 21. What is the complement of the expression x(zy) ? a. x+zy. b. x+(zy). c. x+z+y. d. None of the above. What is the complement of the term abc ? a. a+bc. b. abc. c. a+b+c. d. a+bc. 3- What is the complement of the expression x(zy) ? a. x+zy. b. x+(zy). c. x+z+y. d. None of the above