weird maths questions!? please help!

  • 1 vote

ok, so on this past paper there is a question (calculator based) that confuses me:

"The length of an edge of the larger tetrahedron in four times the length of the corresponding edge of the smaller tetrahedron. the volume of the smaller tetrahedron is 3.8cm^3. calculate the volume of the larger tetrahedron. "

Posted Mon 18th June, 2012 @ 10:27 by AmyPond
Edited by AmyPond on Mon 18th June, 2012 @ 18:39

14 Answers

  • 2 votes

ok...so the length is 4x as big...so the enlargement scale factor of the edges is 4...yes???

to work out the volume scale factor of the shapes...you cube the length scale factor...which is 64...then you times 64 with 3.8...giving you 243.2cm^3 which should be the answer....

Answered Mon 18th June, 2012 @ 19:54 by Namita
  • 2 votes

yes!! thats exactly what i am trying to show you!!! xD xxxxxx i am glad you understood that :) xxxxxxx and you are welcome xD xxxxxx

Answered Mon 18th June, 2012 @ 19:58 by Namita
Edited by Namita on Mon 18th June, 2012 @ 19:59
  • 0 votes

oh so like

scale factor in a ratio = 1 (cubed) : 4 (cubed) ?

oh i get it now:) thank you!

Answered Mon 18th June, 2012 @ 19:57 by AmyPond
  • 0 votes

yeah- it sort of clicked when i visualised it in my head (went into the tetrahedron part of my mind palace);)

Answered Mon 18th June, 2012 @ 20:02 by AmyPond
  • 0 votes

ahhh thats great!! xD xxxx

how was your maths exam in the end?? sorry i couldnt ask on tuesday...been busy trying to clean my room and everything (which still hasnt been done yet -sighs-)

Answered Thu 21st June, 2012 @ 16:43 by Namita
  • 0 votes

Oh yeah you're done!:) it went ok actually:-) what about you? And you are so lucky that you can clean your room instead of revise! No jokes I can't wait until I dont have to worry about revision!:)

Answered Thu 21st June, 2012 @ 23:37 by AmyPond
  • 0 votes

LOL u listened to my advice (mind palace!!)

Answered Fri 22nd June, 2012 @ 07:26 by Dilly
  • 0 votes

Advice?:)

Answered Fri 22nd June, 2012 @ 16:37 by AmyPond
  • 0 votes

my exam was okay-sh...u know...some doubts here and there...but not too bad overall xD ***xx

cleaning room is not fun...it is giving me a headache...but...no more revision...so yeah...its great!! ;) *********xx

when will u be finished with exams??? :) ***

Answered Fri 22nd June, 2012 @ 19:51 by Namita
  • 0 votes

monday 11.30 am ;\ cant wait!

Answered Fri 22nd June, 2012 @ 19:53 by AmyPond
  • 0 votes

Look at my profile picture!

Answered Sat 23rd June, 2012 @ 07:26 by Dilly
  • 0 votes

That is awesome:)

Answered Sat 23rd June, 2012 @ 10:17 by AmyPond
  • 0 votes

LUCIA!!!!!!!!!!!!!! how are you?? its been such a long time... :P xxxx

Answered Thu 5th July, 2012 @ 19:22 by Namita
  • 0 votes

MAY THE ODDS! long time no see! How are you?! XD XD

Answered Thu 5th July, 2012 @ 20:39 by AmyPond