Answer :
answer is 16
8 (6 1/4 x 3.2 - 18)
8 ( 6x4+1) = 25/4
8 (25/4 x 3.2 - 18)
8 (25/4 x 3.2) = 80/4 = 20
8 (20 - 18) = 2
8 x 2 = 16
8 (6 1/4 x 3.2 - 18)
8 ( 6x4+1) = 25/4
8 (25/4 x 3.2 - 18)
8 (25/4 x 3.2) = 80/4 = 20
8 (20 - 18) = 2
8 x 2 = 16