NCERT Solutions for Class 9 Maths Chapter 13 Surface Areas and Volumes (Ex 13.9) Exercise 13.9

Class 10 is a significant academic year for students. Their academic and professional endeavours are impacted by it. Success for a student, however, is not only determined by their performance over the course of a single academic year. The ninth grade is also considered a pivotal point in students’ academic careers since classes 9 and 10are two sides of the same coin. A student must pass Class 9 in order to qualify to take the Class 10 board exams. Additionally, Class 9 offers the outline of the structure of the curriculumfor subsequent classes. The likelihood of performing well on the Class 10 board exams is increased for students who are competent in Class 9 courses. Therefore, students must be persistentin their efforts with regard to Class 9.

There is a considerable likelihood that concepts covered in Class 9 will come up in competitive tests. Therefore, it is important for students to review the academic themes imparted to them in Class 9. The study of Science and Mathematics requires a lot of practice. The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 are among the best resources for learning the subject matter. Students can use this resource to understand how well they understand the main ideas in Class 9 Mathematics and to improve their skills.

The Class 9 syllabus is important since it specifies the themes covered and sets the stage for the Class 10 board exams. As described in the syllabus, research requires a number of prerequisites and tasks. The Class 9 curriculum is critical for students who want to do well in their upcoming board exams. Mathematics experts at Extramarks advise students to learn Class 9 subjects sincerely since they may have an impact on their future academic careers. Whether the impact is positive or unfavourable will depend on students’ preparation for Class 9. The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 and the Class 9 syllabus are available on the Extramarks website. To avail assistance for the Class 9 Mathematics exams, students can refer to the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 . However, it is advised that students read the syllabus before beginning any subject-specific preparation. Students can benefit from this practise by scheduling their preparation efficiently and saving a lot of time. When it comes to studying for exams, time management is essential.Students can improve their time management skills by using the NCERT Solutions for Class 9 Maths Chapter 13 Exercise 13.9 along with other tools and thoroughly studying the curriculum.

In the field of education, NCERT textbooks are one of the most widely used and practical tools, as they serve as a guide for students. With the aid of resources like the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 it is possible to study and prepare for the Class 9 CBSE Textbook effectively. NCERT books give students a firm grasp of the subject by addressing the important ideas covered throughout the course. Students can perform better on tests with a thorough understanding of the NCERT books. When utilised with the NCERT textbook, the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 may further improve students’ chances of succeeding. The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 are composed by subject-matter specialists at Extramarks to help students understand difficult concepts and calculations. Students could greatly benefitfrom using the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 and these solutions might help them get closer to their academic objectives.

The National Council for Educational Research and Training publishes and distributes textbooks for school students across the country. The most remarkable thing about NCERT books for CBSE board exam preparation is that they focus on the conceptual foundation to help students understand the fundamental concepts. The NCERT texts are thorough and complete on their own, and the CBSE rarely asks students to study anything more outside these books.

The mentors of Extramarks advise students to use the NCERT-related materials that are available on the Extramarks website, such as the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9, for a better understanding of NCERT textbooks. The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 and other related resources can be used effectively for both test preparation and classroom studies.

NCERT Solutions for Class 9 Maths Chapter 13 Surface Areas and Volumes (Ex 13.9) Exercise 13.9 

Extramarks’ NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 are created by qualified mathematics mentors.On the Extramarks website, students can also access resources for primary and secondary grade levels that are prepared in a similar fashion to the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9It is strongly recommended that students take advantage of resources such as the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 so that they fully comprehend everything covered in their classrooms. Students are unable to understand the middle and senior secondary school curriculum without a strong foundation in the learning materials used in elementary school classrooms. Students could become disinterested in the subject if there isn’t a strong foundation.. The use of tools developed by Extramarks’ expertise is encouraged to avoid reaching this stage. The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9, among other resources, are easily accessible on Extramarks.

Students can successfully complete  Class 9 Chapter 13 Maths Exercise 13.9 using the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 and other tools specifically designed for this chapter available on the Extramarks website. Using the Maths Class 9 Chapter 13 Exercise 13.9 solutions is an excellent way for students to prepare for the topics covered in the Class 9 Maths Chapter 13 Exercise 13.9, as it can help students understand each question in depth.

In the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9, students can get in-depth solutions to every question in Exercise 13.9 Class 9 Maths, which is the most important requirement for students to understand the concepts taught in Mathematics. Students can comprehend the content more effectively if they spend more time studying the helpful materials, such as NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9.

Access NCERT Solutions for Class 9 Mathematics Chapter 13 – Surface Areas and Volumes 

Students who choose to major in Mathematics may find a variety of fascinating and fulfilling job opportunities. The study of Mathematics can help students improve their problem-solving skills. Students are given skills that they can use in a range of disciplines and professional obligations.

The advantages of earning a degree in Mathematics are numerous. The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 and other tools of a similar nature can actually prove to be valuable for the students who are interested in doing so.

A better understandingof the academic discipline of Mathematics is relevant to many academic and industrial domains. It has an impact with regard to challenges that have an impact on the realworld and their remedies. Humans use concepts of Mathematics for everything, from straightforward tasks like counting and shopping to more difficult ones like Data Analysis. Students are suggested to use the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 and other similar tools accessible on the Extramarks website in order to master mathematical skills.

With a degree in Mathematics, students can contribute to the future development of several areas by gaining a concrete understanding of the topic with the help of assets such as the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9. Whether students choose to specialise in Mathematics or apply the knowledge they acquire in another field, the worldview they acquire in mathematics can help them thrive wherever they goAny student can benefit from knowing Mathematics, regardless of their future aspirations, and can do so by using resources like the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9.

Mathematical problem-solving skills are the foundation of Mathematics. Working on mathematical functions will assist students in becoming more skilled at other sorts of problem-solving in addition to teaching them how to solve challenging mathematical equations, such as:

  • Pattern recognition
  • working in reverse
  • Visualising
  • systematically working
  • utilising logical thinking

Regardless of whether the students choose to pursue a career in Mathematics or in something entirely else, these skills will be beneficial in a variety of vocations and situations. Therefore, it is suggested that students utilise the helpful tools on Extramarks to their greatest potential. To learn the subject of Mathematics, students can refer to the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9.

The skills that students develop in Mathematics can be applied in a range of social and professional settings. In this sense, a degree in Mathematics will provide them with skills that will be useful throughout their lives. A degree in Mathematics can teach students many transferable skills, some of which are listed below:

  • Data Analysis
  • Critical Analysis
  • Time Management
  • Making decisions in Communications

NCERT Solutions for Class 9 Maths Chapter 13 Surface Areas and Volumes Exercise 13.9 

The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 are the solutions to only one of the exercises from Class 9 Chapter 13.. The solutions are for Class 9 Maths Exercise 13.9.More of these resources are created by mentors who have been trained and educated in specific subjects.NCERT Solutions for Class 9

The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 are a reliable source of information for the students of Class 9 because these solutions provide them with step-by-step solutions to all the questions in Exercise 13.9. Students who want to practise the questions from this exercise should consult the NCERT Solutions for Class 9 Maths Chapter 13 Exercise 13.9.The NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9 can be enough for them to practise as well as revise.CBSE Study Materials for Class 9

Mathematics is a subject that is part of everyday life, so it is important for students to understand it.. It can be a challenging subject for many students, but the major reason for that could be a weak conceptual foundation in the subject. E-learning resources available on the Extramarks website can help students form a strong foundation of Mathematics. Among these resources are the NCERT Solutions for Class 9 Maths Chapter 13 Exercise 13.9..

CBSE Study Materials 

Students who wish to master the subject of Mathematics are advised to practise the mathematical questions as much as possible. They can do so with the help of the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9. It is also important to prepare the theorems, formulas, and other theoretical components like definitions, etc. Without this, students might not be able to achieve a high score on the examination.

Q.1 A wooden bookshelf has external dimensions as follows: Height = 110 cm, Depth = 25 cm, Breadth = 85 cm (see Figure). The thickness of the plank is 5 cm everywhere. The external faces are to be polished and the inner faces are to be painted. If the rate of polishing is 20 paise per cm2 and the rate of painting is 10 paise per cm2, find the total expenses required for polishing and painting the surface of the bookshelf.

Ans

Outer surface area=2(110+85)×25+85×110   =2×195×25+9350   =19100 cm2Area​ vertical edges=110×5+110×5   =1100 cm2Area horizontal edges   =75×5+75×5+75×5+75×5   =75(5+5+5+5)   =75×20   =1500 cm2Total external area=19100 cm2+1100 cm2+1500 cm2   =21700 cm2Internal length of each rack of bookshelf=85−5−5=75 cmInternal breadth of each rack of bookshelf=110−203=30 cmInternal depth of each rack of bookshelf=25−5=20​ cmSurface area of a bookshelf=2(75+30)×20+75×30=2×105×20+2250 =4200+2250=6450 cm2Surface area of three bookshelves=3×6450 cm2=19350 cm2Rate of polishing external surface of bookshelf=₹  20100=₹ 0.20 per m2Rate of painting internal surface of bookshelf=₹  10100=₹ 0.10 per m2Total cost of polishing and painting the bookshelf=0.20×21700+0.10×19350=4340+1935=₹ 6275Thus, total expenses required for polishing and painting the surface of the bookshelf is ₹ 6275.

Q.2 The front compound wall of a house is decorated by wooden spheres of diameter 21 cm, placed on small supports as shown in Figure. Eight such spheres are used for this purpose, and are to be painted silver. Each support is a cylinder of radius 1.5 cm and height 7 cm and is to be painted black. Find the cost of paint required if silver paint costs 25 paise per cm2 and black paint costs 5 paise per cm2.

Ans

Diameter of wooden sphere=21 cm      Radius of wooden sphere=212 cm Radius of each cylinder=1.5 cm           Height of each cylinder=7cm           Surface area of sphere=4πr2   =4×227×212×212   =22×3×21   =1386 cm2            Area of top of cylinder=πr2   =227×1.5×1.5   =7.07 cm2Surface area of sphere to be painted   =1386−7.07   =1378.93 cm2Curved surface area of cylinder   =2×227×1.5×7    =66 cm2Cost of silver painting on sphere   =25100   =Rs. 0.25Cost of black painting on cylinder   =Rs. 5100   =Rs. 0.05Cost of painting of one sphere and cylinder    =Rs. 0.25×1378.93+ Rs. 0.05×66   =Rs.(344.7325+3.3)   =Rs.348.0325Cost of painting of eight combinatin of sphere and cylinder   =8×Rs.348.0325   =Rs.2784.26

Q.3 The diameter of a sphere is decreased by 25%. By what per cent does its curved surface area decrease?

Ans

Let diameter of sphere be 2r. Curved surface area of sphere=4π r 2       Decreased radius of sphere=r−25% of r         =r− 25 100 ×r MathType@MTEF@5@5@+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKfMBHbqedmvETj2BSbqefm0B1jxALjhiov2DaerbuLwBLnhiov2DGi1BTfMBaebbnrfifHhDYfgasaacH8MrFz0xbbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=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@B453@         =r−r4        =3 r4New curved surface area of sphere        =4π(3 r4)2        =94πr2Percentage of decreased curved surface area        =4πr2−94πr24πr2×100%        =74πr24πr2×100%        =716×100%        =43.75%Thus,  the 43.75% curved surface area of sphere is decreased.

Please register to view this section

FAQs (Frequently Asked Questions)

1. Is Mathematics a complex subject?

Students might find that Mathematics is a complex and versatile academic discipline and they are eventually required to learn it. In addition, Mathematics is a significant, captivating, and amazing component of the reality of humans. With the aid of Mathematics, cutting-edge discoveries are made feasible in a number of important fields, including Engineering, Science, Commerce, and Technology. Students can learn various themes of Mathematics with the use of the scholarly materials available on the Extramarks website, such as the NCERT Solutions For Class 9 Maths Chapter 13 Exercise 13.9. These resources can help students develop a healthy relationship with the subject.