CAT Exam  >  CAT Questions  >  There is a right circular cone with base radi... Start Learning for Free
There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!?
Most Upvoted Answer
There is a right circular cone with base radius 3 units and height 4 u...
To solve this problem, we need to find the height of the small cone. Let's break down the problem into smaller steps.

Step 1: Calculating the volume and surface area of the original cone
Given that the base radius is 3 units and the height is 4 units, we can calculate the volume and surface area of the original cone using the following formulas:

Volume of a cone = (1/3) * π * r^2 * h
Surface area of a cone = π * r * (r + l)

Where r is the radius and h is the height, and l represents the slant height of the cone.

Step 2: Calculating the volume and surface area of the small cone
Let's assume the height of the small cone is 'x'. We need to find the volume and surface area of this small cone.

Volume of the small cone = (1/3) * π * r^2 * x
Surface area of the small cone = π * r * (r + l')

Here, r is the radius of the small cone, and l' represents the slant height of the small cone.

Step 3: Setting up the equation
The problem states that the volume of the small cone divided by the volume of the frustum (the remaining part) is equal to the painted area of the small cone divided by the painted area of the frustum.

So, we can set up the equation as follows:

(1/3) * π * r^2 * x / [(1/3) * π * (R^2 + R*r + r^2) * (4 - x)] = π * r * (r + l') / [π * (R + r) * l]

Simplifying the equation:

r * x / [(R^2 + R*r + r^2) * (4 - x)] = r * (r + l') / [(R + r) * l]

Step 4: Simplifying the equation
Let's simplify the equation further by canceling out common terms:

x / [(R^2 + R*r + r^2) * (4 - x)] = r + l' / [(R + r) * l]

Step 5: Substituting the values
Now, we can substitute the given values into the equation. The base radius is 3 units, and the height of the original cone is 4 units.

Substituting these values, we get:

x / [(9 + 3r + r^2) * (4 - x)] = r + l' / [(3 + r) * l]

Step 6: Solving the equation
To solve this equation, we need to eliminate the variables. We can do this by using the given information that the plane is parallel to the base.

Since the plane is parallel to the base, the small cone and the frustum have similar triangles.

Using the similar triangles, we can express l' in terms of x and l:

l' / l = x / (4 - x)

Substituting this into the equation, we get:

x / [(9 + 3r + r^2) * (4 - x)] = r + x / (3 + r)

Step
Attention CAT Students!
To make sure you are not studying endlessly, EduRev has designed CAT study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in CAT.
Explore Courses for CAT exam

Similar CAT Doubts

There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!?
Question Description
There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? for CAT 2024 is part of CAT preparation. The Question and answers have been prepared according to the CAT exam syllabus. Information about There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? covers all topics & solutions for CAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!?.
Solutions for There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? in English & in Hindi are available as part of our courses for CAT. Download more important topics, notes, lectures and mock test series for CAT Exam by signing up for free.
Here you can find the meaning of There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? defined & explained in the simplest way possible. Besides giving the explanation of There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!?, a detailed solution for There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? has been provided alongside types of There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? theory, EduRev gives you an ample number of questions to practice There is a right circular cone with base radius 3 units and height 4 units. The surface of this right circular cone is painted. It is then cut into two parts by a plane parallel to the base so that the volume of the top part (the small cone) divided by the volume of the frustum equals the painted area of the top part divided by the painted area of the bottom part. The height of the small cone is A: 7/3 B: 5/4 C: 5/2 D: None of these Please answer it with an explanation!? tests, examples and also practice CAT tests.
Explore Courses for CAT exam

Top Courses for CAT

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev