Math riddle? Please help?!


Question: Math riddle!? Please help!?
I found a stone but did not weigh it; after I added to it 1/7 of its weight and then 1/11 of this new weight, I weighed the total at 1 mana!. What was the weight of the stone!? ( Babylonia 2000-1000 BCE)

1 mana=60 sheqel, and 1 sheqel= 180 se

I know the answer is !.802 mana, but I don't know how to show the work!. Can someone please show me how to do it!? thanks!

Oh, and I think the equation is (x+x/7) + 1/11(x+x+7) = 1Www@Enter-QA@Com


Answers:
Let stone's weight be X
And in order to find anything less than a mana( X is less than mana), find the lower units
So
1 mana = 60 sheqel
and therefore, a mana = 60 * 180 = 10800 se

I will use "se" unit for the example, you can use "sheqel", it works the same!. Just change 10800 to 60 on the equation and re calculate!.

You add 1/7 to stone
x + (1/7 * x)

Then you add 1/11 of the new weight and get 1 mana or 10800 se
(x + (1/7 * x) + (((x + (1 /7 * x)) * 1/11)) = 10800 se

Put /1 for x, since we are adding!. That is to remind us to get the common denominator!.

( x/1 + x/7 ) + (( x/1 + x/7 ) * 1/11) = 10800

Then find common denominator for x/1 + x/7, just times 7/7 to it( x/1 * 7/7)!.
result is 7x + x/7 and that's 8x/7

then secon part, same ( 8x/7 ) * 1/11 = 8x/77

So, now the formular looks like:
( 8x / 7 ) + ( 8x / 77) = 10800

To add, find the LCD again, times 11 to the first set!.

88x/77 + 8x /77 = 10800

96x / 77 = 10800
96x = 10800 * 77

96x = 831600

x = 831600 / 96
______________________________

ANSWER: X = 8662!.5 se -- OR 48!.125 sheqel -- OR 0!.802 mana
Or, to be exact with units -> 48 sheqel and 22!.5 se
______________________________

Check:

X = 8662!.5
Add 1/7 = 1237!.5

New Subtotal = 9900

Add 1/11 of new= 900

Grand total = 10800 se

And 10800 se = 1 mana

PS!. Write the problem out on paper, it's easier to read and understand the adding of fraction with Common denominator thing!.Www@Enter-QA@Com

dont know!.Www@Enter-QA@Com



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