Question 883666
The numbers 75 through 84 would be rounded to 80.
Of those, the only one whose sum of digits is 14 is 77, because 7+7=14.
As you increase the number by 1 from 75 to 84,
the sums of digits increase by 1 from 75 to 79,
for 75, 7+5=12,
for 76, 7+6=13,
for 77, 7+7=14,
for 78, 7+8=15,
for 79, 7+9=16,
and then the sum falls down to 8 for 80, and starts increasing by 1 again,
for 80, 8+0=8,
for 81, 8+1=9,
for 82, 8+2=10,
for 83, 8+3=11, and
for 84, 8+4=12.