SAT Question of the Day #17

Relative humidity is found by dividing the grams of water vapor per cubic meter of air by the maximum possible grams of water vapor per cubic meter of air, then converting to a percentage.  If on a given day the air has 6.7 grams of water vapor per cubic meter, and the maximum possible at that temperature is 19.2 grams of water vapor per cubic meter, what is the relative humidity, to the nearest percent?

A.  19%
B.  30%
C.  35%
D.  67%
E.  87%

The answer is:  C 35%

How do you get to this answer?  Divide the amount of the water vapor per cubic meter, 6.7 grams by the maximum, 19.2 grams.  6.7/19.2 = 0.34896 = 34.896% = 35%  Simple right?