On last week's math test, 32 students received passing grades and 16 students did not receive passing grades. What is the ratio of the number of students who passed the test to the total number of students who took the test?
A. 1/2
B. 2/3
C. 3/2
D. 2/1
B. 2/3
32 students passed the test, while a total of 48 students took the test (32 + 16). Therefore, the ratio of students who passed to the total number of students who took the test is 32/48, which simplifies to 2/3.