OA is different than what I get

Question

jainvik7 · Answer

C for me 

whats the OA ?

SimaQ · Answer

I also got C

V=pi(r^2)*h

h=7
r=3

V=pi9*7=63pi

mbagal1 · Answer

I got E. Can't we have a cylinger with height 6 and radius 3.5(the base sitting on the 8x7 side)? 

That gives us pi*(3.5)^2*6 = 73.5pi.

Fig · Answer

I agree. For a cylendar, we obtain more volume by increasing the radius than by the height.

.... It's due to the root done on the radius : any increase is shapped by the curve x^2 not by a linear rule.

jainan24 · Answer

OA is E, I guess the rule of thumb is first take the face with two largest sides (8 and 7), pick the diameter as smaller of two and then pick the height as the shortest side

Andr359 · Answer

Got E as well. I think that to find the cylinder with the largest volume takes a bit more. LetÂ´s say we have a rectangle box, container, etc. with a than b^2 * a, or, simplifying, whether a * c is < = > than b^2.

khaos · Answer

I agree with Andr359.

For example, the largest cylinder for a cube of sides 4, 6 & 10.

would be obtained by  pi * 2^2 * 10 = 40pi  and not  pi * 3^3 * 4 = 36pi

jainan24 · Answer

I think instead of cube we call it cuboid or rectangular Parallelepiped

andr359 is right

ericttz · Answer

I have seen another one of these. They try to trick you with the the height. Just need to ignore spatial relations and take half the smaller of the largest two dimensions, square it and multiply by pi and third dimension.

Eric

prude_sb · Answer

largest possible radius 7/2

so pi*6*7^2/4 = pi*49*3/2 = pi*73.5


E

OA is different than what I get

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