Question

there are 20 boys and 20 girls in a class. The average percentage marks if the students are more than 70 ,but less than 85 for particular monthly test . The average marks scored by the boys is more than 60,but less than 75.What is the average percentage marks scored by girls?

Answer 1

Answer:

Step-by-step explanation:

For each of the intervals we can get the median average score.

For the total students we have :

(85 + 70)/2 = 155 /2 = 77.5

The total marks is thus :

77.5 × 40 = 3100

For the boys only :

(60 + 75/2) = 135/2 = 67.5

Total marks for the boys is thus :

67.5 × 20 = 1350

The total marks for the girls is thus :

3100 - 1350 = 1750

The average mark scored by girls is :

1750/20 = 87.5