What is 1/1/2 (fraction)?
1 / 1/2 = 1 x 2/1 = 2
If you mean the problem as written: 1 / 1 / 2 = (1 / 1) / 2 = 1 / 2.
However, if you mean it to be: 1 / (1/2), then ElectricPavlov has the answer.