Question 1046419
The numbers are n5, (n+1)5, and (n+2)5
The sum is (n+n+1+n+2+1)5=(3n+4)5, the 1 being from adding 3 numbers that end in 5.  We get 15, and there is a 1 in the tens column.
Check with 25,35,45
n=2 in this instance
(3n+4)=10
The number should be 105.
25+35+45=105