Final answer:
To calculate the GDP deflator, divide the nominal GDP by the real GDP and multiply by 100.
Step-by-step explanation:
To calculate the GDP deflator, we can use the formula:
GDP deflator = (Nominal GDP / Real GDP) * 100
In this case, the real GDP is given as $125 billion and the nominal GDP is given as $150 billion. Plugging these values into the formula, we have: (150 / 125) * 100, which equals 120. Therefore, the GDP deflator is 120.