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skad [1K]
3 years ago
7

the first group of students consists of 10 and their average age was 13 years old the next group consisted of 30 students and th

eir average was 9 years old find the average age of both groups?
Mathematics
1 answer:
Kazeer [188]3 years ago
4 0

Answer: The average was 9 years old find the average age of both groups is 10 years old.

Step-by-step explanation:

Formula foe average : \text{Average} =\dfrac{\text{Sum of all observations}}{\text{Number of observations}}

Given : The first group of students consists of 10 and their average age was 13 years old.

i.e. 13=\dfrac{\text{Sum of ages of students of first group}}{10}\\\\\Rightarrow\ \text{Sum of ages of students of first group}=13\times10=130      (1)

The next group consisted of 30 students and their average was 9 years old.

i.e. 9=\dfrac{\text{Sum of ages of students of next group}}{30}\\\\\Rightarrow\ \text{Sum of ages of students of nextgroup}=9\times30=270      (2)

Then from (1) and (2) , the sum of both groups (first group and next group )students = 130+270 =400

Combined students of both groups (first and next group )= 10+30=40

Now , the average of both groups =\dfrac{\text{Sum of combined students}}{\text{combined students}}

=\dfrac{400}{40}=10

Hence, the average was 9 years old find the average age of both groups is 10 years old.

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