Question #N861
A group of 100 students took a test. The average score on the test was 75. A second group of 50 students took the same test, and their average score was 85. What is the average score of all 150 students who took the test?
A. 78
B. 79
C. 80
D. 81
Correct Answer is: C
The total score of the first group of students is 100 * 75 = 7500. The total score of the second group of students is 50 * 85 = 4250. The total score of all 150 students is 7500 + 4250 = 11750. Therefore, the average score of all 150 students is 11750 / 150 = 80.