Answer:
56 different tests
Step-by-step explanation:
Given:
Number of wires available (n) = 8
Number of wires taken at a time for testing (r) = 5
In order to find the number of different tests required for every possible pairing of five wires, we need to find the combination rather than their permutation as order of wires doesn't disturb the testing.
So, finding the combination of 5 pairs of wires from a total of 8 wires is given as:

Plug in the given values and solve. This gives,

Therefore, 56 different tests are required for every possible pairing of five wires.
4. 119*4 = $476 total dollars for four nights
5.
The answer would be 0 solutions.
Here, we see <em>|</em><em />x+6<em>|</em><em /> = 2.
Oh wow! A foreign object!
|x+6|... two lines... what is that?
That is called absolute value. Whatever is inside the two lines, must have a positive answer!
Let's pretend we have a machine that has this absolute value function activated.
What we put in, we must get a positive answer out.
Let's put in -6.
-6 ==> BEEP BEEP ==> 6
Let's try 3.
3 ==> BEEP BEEP ==>3
Whatever we put in, if it is negative or positive, what comes out is always positive.
So, for how many values <em>x</em> is |x+6|=-2 true?
None, because the answer <em>must</em><em /> be positive!
-2 is not positive, <em>2</em><em /> is.
Answer: x = 28
===================================================
Explanation:
The angles COE, EOF, and FOB combine to form angle COB
angle COB = (angleCOE)+(angleEOF)+(angleFOB)
angle COB = (3x)+(x)+(x+12)
angle COB = 5x+12
----------
Angles AOD and COB are vertical angles, so they are congruent
angle COB = angle AOD
5x+12 = 152
5x = 152-12
5x = 140
x = 140/5
x = 28