Answers

2015-11-19T18:58:28+05:30
first of multiply all term as given
then add their product .
4 x 5 = 20 = 2 + 0 = 2
 3 x 9 = 27 = 2 + 7 = 9
 7 x 3 = 21 = 2 +1 = 3
 4 x 8 = 32 = 3 + 2 = 5
therefor by doing like this we get 5
0