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

You are not logged in.

- Topics: Active | Unanswered

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #241 (three parts) is correct. Neat work, bobbym!

M #242. (a) The area of the base of a cylinder is 36.75 square centimeters and its height is 12 cm. Find its volume.

M #242. (b) How much earth will be excavated from a circular well 17.5 m deep and 2 m base diameter?

M #242. (c) A cylinder of maximum volume is cut out from a solid metal cuboid of length 20 cm and cross section a square side is 14 cm. Find the volume of the metal wasted.

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

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solutions M #242 (a) and (b) are correct. Good work, bobbym!

Please post your reply to M #242 (c).

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

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

M #243. The total surface area of a right circular cylinder is 1540 sq cm. If the height is four times the radius of the base, find the height of the cylinder.

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

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #243 is correct. Neat work, bobbym!

M #244. The ratio of the radius of the base and the height of a cylinder is 2:7, find the radius of the cylinder if its volume is 5632 cc.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #244 is correct. Neat work, bobbym!

M #245. The area of the curved surface of a cylinder is 4400 sq.cm. and the circumference of its base is 110 cm. Find the height of the cylinder.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #245 is correct. Keep it up, bobbym!

M #246. The area of the curved surface of the cylinder is 704 sq.cm. and its height is 8 cm. Find the capacity of the cylinder in liters.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #246 is correct. Neat work, bobbym!

M #247. The minute hand of a clock is 10 cm long. Find the area of the face of the clock described by the minute hand between 8 A.M. and 8.45 A.M.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #247 is correct. Neat work, bobbym!

M #248. A metallic sphere of radius 4.2 cm is melted and recast into the shape of a cylinder of radius 6 cm. Find the height of the cylinder.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #248 is correct. Neat work, bobbym!

M #249. A well with 10 m inside diameter is dug 14 m deep. Earth taken out of it is spread all around to a width of 5 m to form an embankment. Find the area of the embankment.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

Revised problem M #249. A metallic sphere 1 dm in diameter is beaten into a circular sheet of uniform thickness equal to 1 mm. Find the radius of the sheet.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #249 is correct. Excellent, bobbym!

M #250. A spherical shell of lead, whose external diameter is 18 cm, is melted and recast into a right circular cylinder, whose height is 8 cm and diameter is 12 cm. Determine the internal diameter of the shell.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 22,600

Hi;

The solution M #250 is correct. Magnificent, bobbym!

M #251. A well with 10 m inside diameter is dug 8.4 m deep. Earth taken out of it is spread all around it to a width of 7.5 m to from an embankment. Find the height of the embankment.

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

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline