Question

The greatest number which always divides the product of the
predecessor and successor of an odd natural number other than 1,
is

Answer 1

8 is the answer
To be more clear, some examples,
Odd no. be 9
Successor = 10
Predecessor = 8
8×10 =80 , divisible by 8
Now, 19
Predecessor = 18. Successor = 20
18×20 = 360, again by 8
21,
20&22, product is 440, again, 8
Hope it helps