**If 5 x 3 x 2 = 13, 6 x 4 x 3 = 21, 7 x 5 x 4 = 31, 8 x 6 x 5 = 43, 9 x 7 x 6 = 57 Then **10 x 8 x 7 = ??****

5 x 3 x 2 = 13[5*2+3-0=13];

6 x 4 x 3 = 21[6*3+4-1=21];

7 x 5 x 4 = 31[7*4+5-2=31];

8 x 6 x 5 = 43[8*5+6-3=43];

9 x 7 x 6 = 57[9*6+7-4=57];

** 10 x 8 x 7 = ??** [10*7+8-5=73].

so ans is 73.