Let the first number = X
The second number is twice the first, so is 2X
The third number would be 3X-0.5x = 2.5X
Now you have X + 2X + 2.5X = 110
Simplify:
5.5X = 110
Divide both sides by 5.5:
X = 110 / 5.5
X = 20
The first number is 20.
The second number is 2x = 2*20 = 40.
The third number = 2.5x = 2.5*20 = 50.
