Probability that the student got a 'C' GIVEN they are female = number of females that got a C in the test/number of females
From the information given,
number of females that got a C in the test = 12
number of females = 30
Thus,
Probability that the student got a 'C' GIVEN they are female = 12/30
We would simplify the fraction by dividing the numerator and denominator by 6. Thus,
Probability that the student got a 'C' GIVEN they are female = 2/5