Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

50 students of class X planned a visit to an old age home and to spend the whole day with its inmates. Each one prepared a cylindrical flower vase using cardboard to gift the inmates. The radius of cylinder is 4.2 cm  and the height is 11.2 cm  . What is the amount spent for purchasing the cardboard at the rate of Rs.20 per 100  cm 2 ?  


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

Rs.3511.20

b

Rs.3501.20

c

Rs.3511

d

Rs.4511.20 

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

Given that the numbers of students are 50, the radius of a cylindrical flower vase is 4.2 cm  , the height is 11.2 cm  and the rate of cardboard is Rs.20 per 100  cm 2  .
We have the following formula,
The surface area of the cylindrical base =2πrh+π r 2    The surface area of the cylindrical base will be the sum of the curved surface area of the cylindrical flower base and the area of the base.  Then,
r =4.2cm   h =11.2cm   The surface area of the cylindrical base will be,  =2× 22 7 ×4.2×11.2+ 22 7 ×4.2×4.2    =351.12c m 2   The surface area of 50 cylinders,
=50×351.12    =17556c m 2   Then the total cost will be,
=17556× 20 100    =3511.20  .
Thus the total cost of cardboard rate will be Rs.3511.20.
Therefore the correct option is 1.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring