Let’s solve this step by step. :)
First, let’s assign variables for the missing number: x and y.
so the 3 numbers would be x, y and 28
then we have 3 scenarios:
28 + x = 61
28 + y = 76
x + y = 81
Using the first equation, we can get x = 61-28 = 33
Using the 2nd equation, we can get y = 76-28 = 48
then, we can verify if our answer is right by substituting these values in the 3rd equation:
x + y = 81
33 + 48 = 81
81 = 81 ✔️
So the 3 numbers are 28, 33 and 48.
