SAT October, 1, 2011 dicussion

<p>post hard questions ,or essay prompts u have got .. etc</p>

<p>Nice topic please also anybody who post hard question also post there explanation in case if someone open this page before going to exam to get the idea with him aswell.</p>

<p>Good luck to all.</p>

<p>Are people’s live a result of the choices they make? I thought this was hard</p>

<p>A large solid cube is assembled by gluing together identical unpainted small cubic blocks. All six faces of the large cube are then painted red. If exactly 27 of the small cubic blocks that make up the large cube have no red paint on them, how many small cubic blocks make up the large cube?</p>

<p>I know the answer and I know how to solve it, I just put it to keep us going until the exam
answer is 125</p>

<p>^ isnt it 127? if not could you explain it</p>

<p>@krndandaman</p>

<p>Well there are 27 small cubes inside the cube, which is basically 3l/w/h (3^3^3=27).</p>

<p>Anyways what you are trying to find is the number of cubes that is needed to cover the 27, which would be 98. I don’t feel like going in depth but just remember this: to completely cover a cube you need to take the length or side or width (since they are all the same number) and add 2 to it, and this number is the new length/side/width. In this case we know the length/side/width is 3, so we can add 2 to get 5, now just figure out what 5^3 is, and that is your answer.</p>

<p>@SAT100</p>

<p>hmm… I basically imagined a 3x3 cube in my head and logically assumed that you would need the outer layer of a 5x5 cube. 3x3x3 = 27. and the outer layer of a 5x5 cube would be 80… right? 2 sides = 2(5x5) = 50. the other 2 sides would be 2(3x5)=30 right? 50+30+27 gave me 107.</p>

<p>and oops I meant 107 before, not 127 lols</p>

<p>Simple mistake, you forgot the other 2 sides ( I am guessing top and bottom). But the easier way to do it, since you know that it would be a 5x5x5 cube, is just find 5^3.</p>

<p>@SAT100</p>

<p>ahh you are right lol
hopefully i am not as absentminded on the real sat tomorrow :P</p>