What is the relative humidity at 20 degrees if the dew point is 12 degrees?

What is the relative humidity at 20 degrees if the dew point is 12 degrees? The pressure of saturated water vapor at 20 degrees is 2.33 kPa, and at 12 degrees 1.40 kPa.

Given:
Dew point temperature = 12 degrees;
Pressure at 20 degrees = 2.33 kPa;
Pressure at 12 degrees = 1.40 kPa;
Find the relative humidity at t = 20 degrees;

Decision:
Relative humidity at 20 degrees is equal to partial pressure / saturated vapor pressure * 100 percent. That is, we get:
phi = 1.40 kPa / 2, 33 kPa * 100 percent = 1.40 / 2, 33 * 100 percent = 0.6 * 100 percent = 60 percent;
Answer: The relative humidity at 20 degrees is 60 percent.