Answer:
It is sufficient to prove that 
Step-by-step explanation:
The propositions 
being equivalent means they should always have the same truth value. If one of them is true, then all of them must be true. And if one of them is false, then all of them must be false.
Suppose we've proven that (call these first, second and third implications).
If 
was true, then by the first implication that we proved, it would follow that 
is also true. And then by the second implication that we prove it would follow then that 
is also true. Therefore the three of them would be true. Notice the reasoning would have been the same if we had started assuming that the one that was true was either 
. So one of them being true makes all of them be true.
On the other hand, if was false, then by the third implication that we proved, it would follow that 
has to be false (otherwise would have to be true, which would be a contradiction). And then, since is false, by the second implication that we proved it would follow that 
is false (otherwise 
would have to be true, which would be a contradiction). Therefore the three of them would be false. Notice the reasoning would have been the same if we had started assuming that the one that was false was either . So one of them being false makes all of them be false.
So, the three propositions always have the same truth value, and so they're all equivalent.
Answer: 7680
Step-by-step explanation:
1) Which two teams had the greatest point difference?
Delta and Beta (85 - 25 = 60)
2) Which two teams had the least point difference?
Delta and Gamma (85 - 75 = 10)
3) What was the average score of the 5 teams?
(45+25+75+85+65) / 5 = 295 / 5 = 59
4) How many more points did Epsilon score than Beta?
Epsilon: 65
Beta: 25
65 - 25 = 40
Epsilon scored 40 more than Beta
<span>5) Which teams scored more than 2 times Beta’s score?</span>
twice of Beta = 25 x 2 = 50
answer
Gamma (75) , Delta (85) and Epsilon (65)
answer c. none of the above
