Average marks of 15 students of class first is 160. Avearge marks of 10 students of class second is 120. Average marks of 15 students of class third is 180. What will be the average marks of students of all the classes together?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 157.5.
| Understanding/Application |
|
Total marks of 15 students of class first = 15(160) = 2400 Total marks of 10 students of class second = 10(120) = 1200 Total marks of 15 students of class third = 15(180) = 2700 |
| Average = (2400 + 1200 + 2700)/(15 + 10 + 15) = 6300/40 = 157.5 |