If I give my brother 2 marbles I will have double his number of marbles, but my friend will have triple the number I do. The total number of marbles we have together is 63. How many marbles do I have?
Let X be the number of marbles I have.
If I give my brother 2 marbles, I'll have X-2 marbles left.
And my brother will have (X-2)/2 marbles.
And my friend will have (X-2)*3 left.
So the total number of marbles is X-2 + (X-2)/2 + (X-2)*3 = 63.
(X-2)*9/2 = 63.
X-2 = 14.
X = <<16=16>>16 marbles.
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