## Math Brainteaser- Marbles and Rocks

Grandma gave Eli a box containing equal numbers of marbles and rocks. After Eli rolled 36 marbles away, there were 3 times as many rocks as marbles. How many marbles were there to begin with?

*This can be solved without any formal algebra training. Answers can be submitted below, will reveal before the week is over!*

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Falwan| Profile July 25th, 2010 - 10:22 pm++++++++++++++++++++++++++++++++++++++++++++++++

54 MARBLES = 54 ROCKS

++++++++++++++++++++++++++++++++++++++++++++++++

Migrated| Profile July 25th, 2010 - 10:52 pm54

virgolady85| Profile July 26th, 2010 - 1:17 am54

DoodleFish| Profile July 26th, 2010 - 7:35 am54 marbles

starting with equal numbers of rocks and marbles, then have 3x as many rocks as marbles => 2/3 of the marbles were rolled away.

36 x 1.5 =54

engjs1960| Profile July 26th, 2010 - 9:29 am36/2 = 18 + 36 = 54.

Hendy| Profile July 26th, 2010 - 11:21 am54 marbles = 54 Rocks

54 – 36 = 18

18 * 3 = 54

Shawn| PUZZLE GRANDMASTER | Profile July 26th, 2010 - 12:35 pmBut I like algebra!

m=marbles

r=rocks

m=r

When you take away 36 of the marbles, you are left with 1/3 of the original number of marbles.

(m-36)*3=m

m=54

suineg| PUZZLE MASTER | Profile July 26th, 2010 - 9:48 pmOk, I think without algebra could be solved like this:

Intially the proportion were 1::1 , when you substract 36 marbles the proportion goes 1::3

so 2/3 =36 so 1/3 = 18 so initially you have 54 marbles… now that i think about it there was no equation right, so it must be valid for a non algebraic solution, cool.

Hex| PUZZLE MASTER | Profile July 28th, 2010 - 5:55 amsolve x=3(x-36)

x=54 marbles

BlindCupid| Profile July 28th, 2010 - 9:57 am48.

36 / 3 = 12

12 x 4 = 48

prof| Profile August 1st, 2010 - 5:41 pm36/2=18*3=54

RogHyde| Profile November 10th, 2010 - 9:37 amBefore: 54 marbles and 54 rocks

After: 18 marbles and 54 rocks