Let us consider 1 a 4 x 3 = s72
a x 3 results in a number ending in 6
As 16 and 26 is ruled out a is 2
Thus s = 3, t, 4
Now 1 a 4 x b = 8c8 ; b = 2 or 7
Again 2 is ruled out because in that case product would be much less than 800
∴ b = 7 Hence a = 2, b = 7, c = 6, d = 8, s = 3 and t = 4