Question 98445
Let the second number be x
from the problem statement "the third is 11 less than ten times the second"
third number = 10x -11
again from the problem statement "first is 7 more than three times the second"
first number = 3x + 7 

Sum of the numbers  =105

3x+7 + x + 10x-11 =105
14x = 109 
x= 109/14

second number is 109/14
first number = 10* 109/14 -11
             =936/14

third number = 3* 109/14 + 7
             =425/14