If the average marks of three classes of 55, 60 and 65 students are 55,60, 65 respectively, find the average marks of all the students. (In approximately)

यदि 55, 60 और 65 छात्रों वाली तीन कक्षाओं के औसत अंक क्रमशः 55,60, 65 हैं, तो सभी छात्रों के औसत अंक ज्ञात कीजिए। (लगभग)

a) 62.277
b) 66.277
c) 64.277
d) 60.277

Ans : d) 60.277

UP Police Sub Inspector Exam paper – Mathematics

Solution:

To find the average marks of all the students combined, we can use the weighted average formula.

1. Calculate the total marks for each class:
   • Class 1: 55 students x 55 marks = 3025 marks
   • Class 2: 60 students x 60 marks = 3600 marks
   • Class 3: 65 students x 65 marks = 4335 marks
2. Sum the total marks: 3025 + 3600 + 4225 = 10850 marks
3. Sum the total number of students: 55 + 60 + 65 = 180 students
4. Calculate the average marks: Average marks =

So, the average marks of all the students is approximately 60.28.