Question

what will be the sign of the product if a is the product of 5 positive integers and b is the product of 9 negative integers

Answer 1

it will be negative bcz here no of neg. integers is odd...

Answer 2

Positives multiplied with positives give positive.
So no doubt a is positive.
Now if odd no. of negatives are multiplied then the answer is negative.
Like -2*-2=4
But -2*-2*-2=8
Now we have one positive and one negative.
This we get a negative answer.
Hope this helps... :)