India’s No.1 Educational Platform For UPSC,PSC And All Competitive Exam

Download Our App

If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is:

153.33
254.68
355
4None of these

Answer:- 1

Explanation:-

Solution:

\begin{aligned} ∴ Required average \\ = (\frac{55 \times 50 + 60 \times 55 + 45 \times 60}{55 + 60 + 45}) \\ = (\frac{2750 + 3300 + 2700}{160}) \\ = \frac{8750}{160} \\ = 54.68 \end{aligned}

$\eqalign{ & \therefore {\text{Required}}\,{\text{average}} \cr & = \left( {\frac{{55 \times 50 + 60 \times 55 + 45 \times 60}}{{55 + 60 + 45}}} \right) \cr & = \left( {\frac{{2750 + 3300 + 2700}}{{160}}} \right) \cr & = \frac{{8750}}{{160}} \cr & = 54.68 \cr}$

Workspace Report

Post your Comments

", "dateCreated": "7/24/2019 10:09:12 AM", "author": { "@type": "Person", "name": "Nitin Sir" } }, "suggestedAnswer": { "@type": "Answer", "text": "

Solution:

\begin{aligned} ∴ Required average \\ = (\frac{55 \times 50 + 60 \times 55 + 45 \times 60}{55 + 60 + 45}) \\ = (\frac{2750 + 3300 + 2700}{160}) \\ = \frac{8750}{160} \\ = 54.68 \end{aligned}

$\eqalign{ & \therefore {\text{Required}}\,{\text{average}} \cr & = \left( {\frac{{55 \times 50 + 60 \times 55 + 45 \times 60}}{{55 + 60 + 45}}} \right) \cr & = \left( {\frac{{2750 + 3300 + 2700}}{{160}}} \right) \cr & = \frac{{8750}}{{160}} \cr & = 54.68 \cr}$ ", "dateCreated": "7/24/2019 10:09:12 AM" } }

Test

Classes

E-Book