Question

Three Science classes A, B and C take a Life Science test.

The average score of class A is 83. The average score of

class B is 76. The average score of class C is 85. The

average score of class A and B is 79 and average score of

class B and C is 81. Then the average score Of classes A,

B and C is?

Answer 1

average = mean
finding mean - sum of the digits / number of the digits
a +b+c /3
83 + 76 + 85 /3
244/3 = 81.333
81.333 is the average  score of a,b,c
please mark mine as BRAINLIEST answer

Answer 2

Answer:

The average of A, B and C is 81.5

Step-by-step explanation:

The average value of A is 83 and B is 76.

The average score of A and B is 79.

Hence the ratio of A : B = 3 : 4

The average of B is 76 and C is 85.

The average value of B and C is 81.

Hence the ratio of B :C = 4 : 5

The average score of class A,B and C is $\frac{3(83)+4(76)+5(85)}{3+4+5}=\frac{249+304+425}{12}=$ 81.5.