Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

The solution M#567 is correct. Keep it up, Monox D. I-Fly!

M # 568. Surface area of a hemisphere is

square centimeters. Find the volume of the sphere.It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 569. The base radius of a cylindrical block of wood is 15 centimeters and its height is 40 centimeters. What is the volume of the largest cone that can be carved out of from this? Use

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 2,000

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.

May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

.

The solution M # 569 is correct. Neat work, Monox D. I-Fly!

M # 570. A cone of maximum size and 16 centimeters of height is cut off from a solid sphere of 10 centimeters radius. How much part of the volume of the cone is the volume of the sphere?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

.

M # 571. Find the area of a paper needed to cover a square pyramid of base edge 42 centimeters and lateral edge 29 centimeters.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 572. A solid metal cylinder is of base radius 12 centimeters and height 20 centimeters. By melting and recasting, how many cones of base radius 4 centimeters and height 5 centimeters can be made?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

.

M # 573. A sector of central angle 216° is cut out from a circle of radius 25 centimeters and is rolled up into a cone. What are the base radius, height, and the volume of the cone? Use

.Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 574. The largest sphere is carved out from a cube. If the volume of the sphere is

cubic centimeters. Find the volume of the cube.Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 575. A metal cylinder of base radius 4 centimeters and height 10 centimeters is melted and recast into spheres of radius 2 centimeters. How many such spheres are got?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 2,000

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.

May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

The solution M # 575 is correct. Brilliant, Monox D. I-Fly!

M # 576. A solid metal sphere with radius 12 centimeters is melted and made into 27 equal small spheres. What is the radius of a small sphere?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**666 bro****Member**- From: Flatland
- Registered: 2019-04-26
- Posts: 586

Hi

The solution of M# 576 is 4cms

"An equation for me has no meaning, unless it expresses a thought of God"- Srinivasa ramanujan

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

The solution M # 576 is correct. Excellent, 666 bro!

M # 577. The ratio of the base radii of two cones is 3 : 5 and their heights are in the ratio 2 : 3. What is the ratio of their volumes?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**666 bro****Member**- From: Flatland
- Registered: 2019-04-26
- Posts: 586

Hi,

Solution is 6:25

*Last edited by 666 bro (2019-10-17 02:36:47)*

"An equation for me has no meaning, unless it expresses a thought of God"- Srinivasa ramanujan

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi 666 bro,

.

The solution M # 577 is correct. Brilliant!

#M # 578. The edge of a cube is 12 centimeters. Find the volume of the largest sphere that can be carved out from it. (In terms of pi).

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 579. A sector of central angle 216° and radius 25 centimeters has been rolled up to form a cone. Find the radius, height, and volume of the cone.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 580. The ratio of the radius and slant height of a cone is 2 : 3. Find the central angle of the sector to make the cone.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 581. A square of side 5 centimeters and four isosceles triangles of base 5 centimeters and height 8 centimeters are put together to make a square pyramid. How many square centimeters of paper is needed?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 2,000

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.

May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

The solution M # 581 is correct. Neat work!

M # 582. The perimeter of the base of a square pyramid is 40 centimeters and the total length of all its edges is 92 centimeters. Calculate its surface area.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 583. A toy in in the shape of square pyramid has base edge 16 centimeters and slant height 10 centimeters. 500 of these are to be painted and the cost is $80 per square meter. What would be the total cost?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 584. What is the central angle of the sector needed to make a cone of base radius 10 centimeters and slant height 25 centimeters?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 585. What is the base radius and slant height of the cone made by rolling up a sector of radius 10 centimeters and central angle 60°?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 586. What is the ratio of the base radius and slant height of the cone made by rolling up a semicircle?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 31,677

Hi,

M # 587. What is the curved surface area of a cone of base radius 12 centimeters and slant height 25 centimeters approximately?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline