Students of three different classes appeared in common examination. Pass average of 10 students of first class was 70%, pass average of 15 students of second class was 60% and pass average of 25 students of third class was 80% then what will be the pass average of all students of three classes?
A. 74%
B. 75%
C. 69%
D. 72%
Answer: Option D
Solution(By Examveda Team)
$$\eqalign{ & {\text{Sum}}\,{\text{of}}\,{\text{pass}}\,{\text{student}}\,{\text{}}\,{\text{first,}}\,{\text{second}}\,{\text{and}}\,{\text{third}}\,{\text{class}}, \cr & = \left( {70\% \,{\text{of}}\,10} \right) + \left( {60\% \,{\text{of}}\,15} \right) + \left( {80\% \,{\text{of}}\,25} \right) \cr & = 7 + 9 + 20 = 36 \cr & {\text{Total}}\,{\text{students}}\,{\text{appeared}}, \cr & = 10 + 15 + 25 = 50 \cr & {\text{Pass}}\,{\text{average}}, \cr & = 36 \times \frac{{100}}{{50}} = 72\% \cr} $$This Question Belongs to Arithmetic Ability >> Average
Join The Discussion
Comments ( 6 )
Related Questions on Average
A. 125 km/hr
B. 75 km/hr
C. 135 km/hr
D. 120 km/hr
Sum of pass student first,second,thrid
(70%of10)+60%of15)+(80%of25)
7+9+20=36 this is total pass mark
Sum of Total students= 10+15+25=50
Then we can get pass averege of all students by this formula
Pass average= Total pass mark /total no of students ×%
36/50*100= 72 is the correct answer 🙏 sorry for previous ansewer the correct answer is 72 thank U
To find the pass average of all students from the three classes, we need to calculate the weighted average based on the number of students in each class.
Let's calculate the total number of students and the total pass marks for all three classes:
First class: 10 students with a pass average of 70%.
Total pass marks for the first class = 10 * 70% = 7 * 10 = 70.
Second class: 15 students with a pass average of 60%.
Total pass marks for the second class = 15 * 60% = 9 * 15 = 135.
Third class: 25 students with a pass average of 80%.
Total pass marks for the third class = 25 * 80% = 20 * 25 = 500.
Now, calculate the total number of students:
Total number of students = 10 + 15 + 25 = 50.
Calculate the total pass marks for all students:
Total pass marks = 70 + 135 + 500 = 705.
Finally, calculate the pass average for all students:
Pass average = (Total pass marks / Total number of students) * 100%
= (705 / 50) * 100%
= 14.1 * 100%
≈ 74%.
Therefore, the pass average of all students from the three classes is approximately 74%.
The closest option to 74% is option A. 74%.
Why the calculation is 36*(100/50)
Hello Nayan, the value come 7 + 9 + 20 By solving the precentage.Kind check the below
= (70% of 10) + (60% of 15)+ (80% of 25)
= (70/100 X 10) + (60/100 X 15)+ (80/100 X 25)
=7 + 9 + 20 = 36
Please explain
How is the 7+9+20=36