Answer is simple. We have to use factorial to get 120.
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( 0! + 0! + 0! + 0! + 0! ) ! ( 1 + 1 + 1 + 1 + 1 ) ! (5)! = 5*4*3*2*1 = 120 |
Let me explain how o!=1.
We know that, n! can be defined as below.
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n!=n*(n-1)! |
substitute n=1.
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1!=1(1-1)! 1!=1(0)! 1=0!; |
So 0!=1