Ateacher gave his class two quizzes; 80% of the class passed the first quiz, but only 60% of the class passed both quizzes. what percent of those who passed the first quiz also passed the second quiz? (2 points)

20%
40%
60%
75%

To answer the problem above, let x be the total number of students in the class. If only 80% of the class passed the first quiz, it may be represented as 0.8x. 

Only 60% of the class passed the second quiz, which is represented as 0.6x. To determine the percent of the first quiz passers who also passed the second test. Divide 0.6x by 0.8x and multiply by 100%. The operation gives 75%. 

D.