There are 120 student in class in which 20 of them are girls and rest boys.if the average marks in math of boys is 65% and that of girls is 80%. find the average marks of the class
I think it would be:
avg = (20(80) + 100(65))/120 = 67.5
Please solve questions and give a full answer
To find the average marks of the class, we need to calculate the total marks of all the students and divide it by the total number of students.
First, let's find the total marks obtained by the boys. We know that the average marks of the boys is 65%. Since we don't have the exact number of boys, we'll represent it as 'x'.
So, total marks obtained by the boys = (65/100) * x
Now, let's find the total marks obtained by the girls. We know that the average marks of the girls is 80%. Since we know there are 20 girls, we can calculate their total marks directly.
Total marks obtained by the girls = (80/100) * 20 = 16 * 20 = 320
We also know that the total number of students is 120.
Now, we can calculate the total marks obtained by the entire class.
Total marks obtained by the class = total marks obtained by the boys + total marks obtained by the girls
Total marks obtained by the class = (65/100) * x + 320
Since the average marks of the class is the total marks obtained by the class divided by the total number of students, we can use the formula:
Average marks of the class = Total marks obtained by the class / Total number of students
Average marks of the class = [(65/100) * x + 320] / 120
Now, you can substitute the value of 'x' (the number of boys) into the formula to get the average marks of the class.