If n is a positive integer, what`s the tens digit of n?
1) The hundreds digit of 10n is 6
2) The tens digit of n + 1 is 7
1) 10n will just add a 0 to the units place and shift every digit by 1 to the left; that's all.
If Hundred's place of 10n = 6; Ten's place of n must be 6
If n=69; n+1=70;
If n=73; n+1=74;
So; ten's place of n+1 is 7 for both the values discussed above.
Thus; ten's place of n may be 6 or 7.
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