Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 9 Answered

A hollow cylindrical tube, open at both ends is made of iron 1 cm thick. If the external diameter is 14 cm and the length of tube is 70 cm, Find the cost of painting its inner surface at the rate of Rs. 4 per cm2.
Asked by Topperlearning User | 12 Oct, 2017, 08:09: AM
answered-by-expert Expert Answer

External diameter = 14 cm, Internal diameter = 12 cm.

Internal radius (r) = 6 cm, Length of the tube (h) = 70 cm

Let S be the inner curved surface area.

 

begin mathsize 12px style straight S space equals space 2 πrh straight S space equals space 2 cross times 22 over 7 cross times 6 cross times 70 space cm squared straight S space equals space 2640 space cm squared end style

 

Cost of painting 1 cm2 = Rs. 4

Therefore, cost of painting 2640 cm2 = Rs. (2640 x 4) = Rs. 10560

Answered by | 12 Oct, 2017, 10:09: AM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 9 - Maths
To find formula for the curved serface area of right circullar cylender expermentally
Asked by lalchandkundara17 | 30 Dec, 2022, 08:44: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
What is the volume of a right circular cylinder whose base area is 606cm² and whose height is 2m
Asked by devanshuraval240 | 07 Nov, 2020, 09:34: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
The radius of a right circular cylinder with curved surface area of 440 cm2 and an altitude of 5 cm is
Asked by swatipuspapatel | 17 Oct, 2020, 07:50: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
the radius of sphere is 2r, then its volume will be?
question image
Asked by taragiunnati | 02 Jun, 2020, 08:39: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
a cylindrical vessel filled with water has internal diameter 7.8cm and height 28cm. it's entire water is put in a rectangular tube whose base is a square of side 26cm.find the height of water in tube?
Asked by shivampandey2248 | 20 Nov, 2019, 12:59: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
find the diameter of a cylinder whose height is 5cm and numerical value of volume is equal to numerical alue of curved surface area  
Asked by tanmayambika | 08 Jun, 2019, 03:03: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
A hollow cylindrical tube, open at both ends is made of iron 1 cm thick. If the external diameter is 14 cm and the length of tube is 70 cm, Find the cost of painting its inner surface at the rate of Rs. 4 per cm2.
Asked by Topperlearning User | 12 Oct, 2017, 08:09: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
The diameter of a roller 1 m long is 56 cm. If it takes 200 revolutions to level a playground, find the cost of levelling the playground at the rate of 50 paisa per m2.
Asked by Topperlearning User | 12 Oct, 2017, 07:56: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
Find the lateral surface area (curved surface area) of a hollow cylinder open at the ends of length is 14 cm, the external diameter is 10 cm and the thickness is 2 cm.
Asked by Topperlearning User | 12 Oct, 2017, 08:11: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Maths
If 1 m2 of sheet costs Rs. 400. Find the cost of sheet required to make a closed cylindrical tank of height 1.4 m and base diameter 210 cm.
Asked by Topperlearning User | 12 Oct, 2017, 08:05: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Grab Our Exam Special Offer-Enrol now!
×