Who should be the winner?Part-II
The numbers from1 to 20 are written in a row. Two players, Andy and Michael take turns putting plus signs and minus signs between the numbers. When all such signs have been placed, the resulting expression is evaluated (i.e. the additions and subtractions are performed). Andy wins if the sum is even, and Michael wins if the sum is odd. Who has a winning strategy??
Andy makes the first move.
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The parity of the result does not depend on the position of the pluses and minuses,but only on the number of odd integers in the original set of numbers.Since there are 10 odd integers to begin with,and 10 is an even number,the first player will win.