The average score of class X, Y, Z are 83, 76, 85. The ratio of number of students in three classes is 24, 32 and 40 respectively. Find the combined average of the all three classes.
Answer & explanation
Correct answer: option 1
x : y : z
No. of students 24 : 32 : 40
3 : 4 : 5
Average 83 76 85
Sum 249 304 425
Average of x, y, z (combined) = \(\frac{249 + 304 + 425}{12}\) = 81.5