Answer:
The number of girls participated in quiz is 40 .
Step-by-step explanation:
Given as :
Total number of students took quiz = 100
Average score of 100 students = 76 points
The Average score of boys = 80 points
The Average score of girls = 70 points
Let The number of boys participated in quiz = b
Let The number of girls participate in quiz = g
Now, According to question'
Total number of students took quiz = number of boys participated in quiz + number of girls participated in quiz
Or, b + g = 100 ........A
<u>Again</u>
∵ Average score of 100 students = 76 points
∴ Total score of 100 students = 76 × 100 = 7600
So, Average score of boys × number of boys participated + Average score of girls × number of girls participated = Total score of 100 students
Or, b × 80 + g × 70 = 7600
Or, 80 b + 70 g = 7600 .........B
Now, Solving equation A and B
(80 b + 70 g ) - 70 ×( b + g ) = 7600 - 70 × 100
I.e (80 b - 70 b) + (70 g - 70 g) = 7600 - 7000
Or, 10 b + 0 = 600
∴ b =
i.e b = 60
So, The number of boys participated in quiz = b = 60
Put the value of b into eq A
∵ b + g = 100
So, g = 100 - b
Or, g = 100 - 60
i.e g = 40
So, The number of girls participated in quiz = g = 40
Hence, The number of girls participated in quiz is 40 . Answer