<p>Also, can anybody confirm that there was a really easy question about distance in a three dimensional space where you just used distance formula for x, y, and z values? I’m pretty sure there was but I think I misread it and got it wrong.</p>
<p>Distance formula is given some point (e,f,g) and some equation ax + by + cz + d is :</p>
<p>ab(a(e)+b(f)+c(g)+d)/((a^2+b^2+c^2)^1/2))</p>
<p>@LoveA2Trig The answer was just 1/x because the inverse function of 1/(x-1) (±)1 doesnt look identical to the function 1/(x-1) (±) 1. You can even graph it online </p>
<p>was the answer for the chairs question E? i remember choosing the last choice.</p>
<p>Uh yes it does…pm me or somethin @gkdld3131 </p>
<p>can you tell me what the question about the chairs was and what answer choices there were</p>
<p>The chairs problem asked how many chairs each row could NOT have contained if the last row had 5 empty chairs, and there were 355 chairs total…
I believe some of the answer choices were; 10, 15, 25, 2 others :P. The correct answer is 25. If there were 25 chairs in each row the last one would have 20 empty seats.</p>
<p>was 25 choice E?</p>
<p>Choice E FOR that question was 25?</p>
<p>For the interest rate one did anybody use the rule of 72 to see how long it would to double it?
So much easier than using logs
You just do 72 divided by the interest rate and you’re good to go. So 72/(8/12) since they wanted it in months and I got 108.
Learned that in my personal finance class and it’s always worked</p>
<p>Hey was the answer to the chairs question E) 25 ?</p>
<p>@gkdld3131 - Yes. And the answer to the inverse functions was i and iii ((1/(x-1)) +1 or whatever choice iii was, was identical to it’s inverse function).</p>
<p>Okay but for that chair question i wanna know if 25 was choice E</p>
<p>And if you graph iii’s inverse it doesnt look like its original function</p>
<p>The chair question was indeed E). 25.</p>
<p>As for the function question, how are you graphing iii’s inverse function? If you try to find the inverse function you get the exact same function:</p>
<br>
<br>
<p>Alternately, you could pick any number and run it through the equation twice:
x=3;
1/(3-1) + 1 = 1/2 + 1 = 1.5
x = 3/2;
1/(1.5 - 1) + 1 = 2 + 1 = 3
So clearly running it the second time undid the original function, thus it is its own inverse.</p>
<p>@nerdfighter23 The rule of 72 and others similar to it are rules for quick mental calculations or if you only have a basic calculator at hand. Arriving at 108 months is only an approximation of the correct answer: 105 months. I’d imagine the rule would work better if the question wanted the answer in years not months since the error margin would be smaller and chances are both answers would round up to the same number. </p>
<p>@rafaelesf Aw man. Guess I screwed that one up. I mean, I got like 107.99 so I just rounded up</p>
<p>If the question wanted the answer in years, then both methods would yield 9 years as the answer. </p>
<p>Guys do you remember wether or not 19 was the question about x+y=w+z or something? </p>
<p>No. 19 was the answer to the question asking for a counterexample to the statement that if p is prime, 2p+1 is prime.</p>
<p>Edit: if you’re asking if x+y=w+z was question number 19, good luck finding someone who remembers question numbers. I certainly don’t. But FWIW I think that question was a lot later than 19.</p>