Question

I need the answer quick

Answer 1

Answer:

83.6

Step-by-step explanation:

total number of the class

= (12+18 )

=30 members

12 members had 80

18 members had 86

let the total marks had by the 12 members be x

also let the total marks had by the 18 members be y

80=$\frac{x}{12}$

x=80×12

x=960

86=$\frac{y}{18}$

y=86×18

y=1548

The average class mark

= $\frac{x+y}{30}$

=$\frac{1548+960}{30}$

=$\frac{2508}{30}$

=$\frac{418}{5}$

=83.6

the average class mark is 83.6