Products of four numbers would be positive if all 4 are positive or all 4 are negative or two are positive and 2 are negative
PPPP P 9C4/14C4 = 126/1001
NNNN P 5C4/14C14 = 5/1001
PPNN P 9C2*5C2/14C4 = 360/1001
As a toddler when I looked at my fingers and wondered,
you helped me to count numbers.
As a kid when I looked at stars with awe,
you helped me and told that's infinity.
As a teen when my confused mind often went blank,
you told that's zero and eventually
vinotha
In mathematics the art of proposing a question must be held of higher value than solving it.
...Georg Cantor ( inventor of set theory)