If the product of six whole numbers is an odd whole number, exactly how many of these whole numbers must be odd

Question

A) two

B) three

C) four 

D) five 

E) six

Answer 1

An odd number contains no factors of 2.  If you have a product of six numbers that must be odd, then none of those six numbers can have a factor of 2, which means that none of them can be even, which means that all six of them must be odd.