Which of the following disjunctions is false ?A. 4 - 3 = 2 or 6 · 3 = 9B. 5 · 6 = 30 or 3 + 4 = 7C. 8 + 3 = 11 or 5 · 4 = 23D. 7 + 6 = 13 or 5 · 2 = 10
Accepted Solution
A:
A disjunction is false if both parts of the disjunction are false; otherwise, it is true ---------------------------------------------- Choice A
4-3=2 is false 6*3=9 is false
both parts are false, so overall the entire disjunction is false ---------------------------------------------- Choice B
5*6=30 is true 3+4=7 is true
Neither part is false, so overall the entire thing is true ---------------------------------------------- Choice C
8+3=11 is true 5*4=23 is false
While second piece is false, the overall disjunction is true. The first part (true) makes the whole thing true. ---------------------------------------------- Choice D
7+6=13 is true 5*2=10 is true
Neither part is false, so overall the entire thing is true ---------------------------------------------- ---------------------------------------------- In summary, we have
A. False B. True C. True D. True
Making choice A the only answer that is false. So choice A is the final answer