Average (mean) = (sum of all the data) / (# of data)
sum of all the data = (average)(# of data)
Thus for 100 students with an average of 93,
sum of all data = (93)(100) = 9300
and for 300 students with an average of 75,
sum of all data = (75)(300) = 22500
Therefore you would expect the overall average to be
(9300 + 22500) / (100 + 300) = 79.5 %
Now if there are x # of advanced students and y # of regular students, then
x + y = 90 (total # of students) and 93x + 75y = 87(x + y) (overall average)
The second equation can be simplified to x - 2y = 0
Subtracting the two equations yields
x = 60 and y = 90
Therefore you would need 60 advanced and 30 regular students.
Answer:
3.2
Step-by-step explanation:
For this we need to get the entire volume of the mixture. We get it by summing each quantities:
Vol = 10.6 + 0.6 + 8 = 19.2 L
So, we have 19.2 L for 6 bowls.
For getting the punch of each bowl we just need to divide this volume between the 6 bowls:
19.2 / 6 = 3.2 L
So, each bowl has 3.2 L
The value of x is 243
(correct me if wrong)
