# Mathematical Expressions

• Mar 24th 2013, 09:03 PM
geniusgarvil
Mathematical Expressions
When writing a math expression, any time there is an open bracket "(", it is eventually followed by a closed bracket ")". When we have a complicated expression, there may be several brackets nested amongst each other, such as in the expression (x+1)((x2)+3(x4)×(x^2+7×(3x+4))). If we removed all the symbols other than the brackers from the expression, we would be left with the arrangement ()(()()(())). For any arrangement of brackets, it could have come from a valid mathematical expression if and only if for every place in the sequence, the number of open brackets before that place is at least as large as the number of closed brackets. If 34 open brackets and 34 closed brackets are randomly arranged, the probability that the resulting arrangement could have come from a valid mathematical expression can be expressed as a/b where a and b are coprime positive integers. What is the value of a+b?
• Mar 27th 2013, 03:21 AM
abhishekthakur
Re: Mathematical Expressions
answer is 1/7 so a+b is 8 but please dont post brilliant problems here it is cheating...
• Mar 27th 2013, 07:00 PM
geniusgarvil
Re: Mathematical Expressions
Man 8 is incorrect. I too had posted 8 only....
• Mar 28th 2013, 01:56 AM
GeorgeWashington
Re: Mathematical Expressions