CLEAR
Toprankers-Info

+91 7676564400

Mobile App

Get it on Google Play
Discussions
Select Date
Tags:

Articles

Discussions
Submit Discussion
RIYAZ KHAN

· started a discussion

· 1 Months ago

solution (Question: 109018.0 )

2*22/7*r1=88
r1=14
2*22/7*r2=132
r2=21
r2-r1=7
22/7(r1-r2)^2=22/7*7*7
154
is this correct?

Question:

Find the area between two concentric circles of circumference 88 cm and 132 cm.

Options:
A) 780 cm2
B) 770 cm2
C) 715 cm2
D) 660 cm2
Solution:
Ans: (b) Let the radius of the inner circle be r1 and the radius of the outer circle be r2.

A.T.Q.,


Knowledge Expert

· commented

· 1 Months ago

Dear student,

Given Answer is correct, In your explanation r2= 21 and r1= 14 area between the concentric circle= pai r2^2- pai r1^2= pai (21^2- 14^2) = pai (21+14)(21-14) by { a^2-b^2= (a-b)(a+b)} =
= pai (21+14)(21-14)
= 22/7 (35)(7) = 770 cm^2

Keep learning Keep solving
Best wishes
Team Toprankers
-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