A class of 30 students appeared in a test. The average score of 12 students is 62, and that of the rest is 74. What is the average score of the class?

Options
a) 67.2
b) 68.2
c) 69.2
d) 70.2

Solution

As per question
Total No. of students appeared in a test = 30
Average score of 12 students = 62
average score of the rest students = 74
Average =
Total score of 12 students = Average score of 12 students x No. of students
Total score of 12 students = 62 x 12 = 744
No. of students left = 30 – 12 = 18
Total score of 18 students = Average score of 18 students x No. of students
Total score of 18 students = 74 x 18 = 1332
Total scores = 744 + 1332 = 2076
Average =
Average = = 69.2

Answer : 69.2