Multiply two numbers who differs from a small even no.

its so simple...


When two numbers differ by two their product is always the square of the number in between them minus 1.
12×14 = (13×13)-1 = 168.
16×18 = (17×17)-1 = 288.
99×101 = (100×100)-1 = 10000-1 = 9999


If two numbers differ by 4 then their product is the square of the number in the middle (the average of the two numbers) minus 4.
11×15 = (13×13)-4 = 169-4 = 165.
13×17 = (15×15)-4 = 225-4 = 221.


If the two numbers differ by 6 then their product is the square of their average minus 9.
12×18 = (15×15)-9 = 216.
17×23 = (20×20)-9 = 391.
isnt it very easy...
u dont need to be genius..