Question

fill in the next line
9 7 5 9 4 9
6 3 4 5 3 6
1 8 2 0 1 8
?
give a reason

Answer 1

 see in 1st line 
      975949
 9*7=63
5*9=45
4*9=36
and second line is 634536 means their products
then second line is 634536
6*3=18
4*5=20
3*6=18
and third line is 182018 means product of second line numbers in pairs
then third line is 182018
1*8=8
2*0=0
1*8=8 
means the fourth line should be 808 

Answer 2

It's a easy riddle -
975949= 9*7 = 63
             5*9 = 45
             4*9 = 36
634536= 6*3 = 18
             4*5 = 20
             3*6 = 18
182018= 1*8 = 8
              2*0 = 0
              1*8 = 8
              
               =808 answer

reason- the second no. is the product of first and third is the product of second so that's why fourth is the product of third

hope it helps