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Comment on Working with Formulas
I guess you can just ignore 1
so
plug in r=1, h=1 --> 1^2*1 = 1
plug in r=1/2 h=2 --> ((1/2)^2))*2 = 1/2
should always work for these problems
Hey Brent,
two thingies: The link underneath isn´t active anymore, do you have another one?
Also: In the example, if I don´t use values but simply change r to 1/2 r and h to 2h, it basically canceles back to the original formula. How come? I guess my first intiution would have been to take ANS C; K=K.
Thanks for the heads up! I've
Thanks for the heads up! I've fixed that link.
Your approach to the question is perfectly valid.
However, we need to recognize that we're squaring the r term, but not squaring the h term.
So, if the radius = r and the height = h, the volume = (1/3)πr²h = K
If the radius = r/2 and the height = 2h, the volume = (1/3)π(r/2)²(2h)
= (1/3)π(r²/4)(2h)
= (1/3)π(r²/2)h
= (1/3)πr²h/2 = K/2
Does that help?
Cheers,
Brent
Now I see, thanks for the
Thank you, totally got it now
Hi Brent,
For the second link, I solved this by plugging 45 for F-32 then solved for C. Is this method correct?
Question link: https:/
Question link: https://gmatclub.com/forum/if-c-is-the-temperature-in-degrees-celsius-an...
Unfortunately, that approach won't work.
To help understand why this is the case, let's see what would happen if the question said the temperature extremes differed by 32 degrees on the Fahrenheit scale (instead of 45 degrees).
If we plugged in F = 32, the equation, 9C = 5(F – 32), would become: 9C = 5(32 – 32).
When we solve that equation for C we get C = 0
In other words, a temperature difference of 32° Fahrenheit would be the equivalent of a temperature difference of 0° Celsius.
This makes no sense.
In my solution (https://gmatclub.com/forum/if-c-is-the-temperature-in-degrees-celsius-an...), I take two temperatures in Fahrenheit that differ by 45°(32° and 77°), convert those temperatures to Celsius, and then determine the temperature difference in Celsius.
Notice that we can use any two temperatures (in Fahrenheit) that differ by 45°
If you convert them to Celsius and then calculate the difference, you will always get a difference of 25° Celsius
Thanks Brent. This is clearer