CLEAR
Toprankers-Info

+91 7676564400

Mobile App

Get it on Google Play
Discussions
Select Date
Tags:

Articles

Discussions
Submit Discussion
Rahul Kumar Thakur

· started a discussion

· 1 Months ago

soln (Question: 398331.0 )

please provide a soln....

Question:

A class consists of 20 boys and 30 girls. In  the mid semester examination, the average   score of the girls was 5 more than of boys'. In the final exam, however, the average score of the girls dropped by 3 while the average score of entire class increased by 2. The increase in the average score of the boys is –

Options:
A)

10

B)

4.5

C)

9.5

D)

6

Solution:

Ans: (c)


jishnu r

· commented

· 1 Months ago

let avg mark of boys in midterm=x , girls=x+5

total mark of students in midterm = 20*x +30(x+5)=50x + 150

avrg of class in midterm=(50x + 150)/50= x+3

Now in final exam girls avg decrease 3 , so the avg of girls=x+5-3= x+2

also clss avg increases by 2 that means=x+3+2=x+5

total mark of cls=(x+5)*50=50x+250 -----------------------(1)

let the avg of boys increases by 'k'

then total mark of clss=(x+k)20 + (x+2)30-----------------(2)

(1)=(2);

50x+250=(x+k)20 + (x+2)30=50x+20k+60

190=20k; k =9.5
-logo
We at aim to provide most comprehensive content & test for practice which is carefully divided into various chapters and topics to help you focus on your weak areas.Our Practice mock test gives you unmatched analytics to help you realize your strong areas,time management and improvement areas.Our Short & Crisp notes on each topic will help you to quickly revise the topic along with the tips & tricks of the exams.
More About
-Info
-Info

Mobile App

Get it on Google Play
About Us Campus Ambassador Careers Contact Us Refund Policy

All Rights Reserved Top Rankers

User Policy
Disclaimer
Terms & Conditions