Math Is Fun Forum

reconsideryouranswer

Member

Registered: 2011-05-11

Posts: 171

Re: 10 second questions

#2973. What is the maximum length of a pencil that can be kept in
a rectangular box of dimensions 8 cm x 6 cm x 2 cm?

#2974. Find the length of the longest rod that can be placed in a
room 16 m long, 12 m broad, and

m high.

ganesh,

I understand the intent of these questions, #2973 and #2974, but the answers
do not work.

#2973
The pencil, whether sharpened (at one end) or not sharpened at all,
would not fit along a longest diagonal of the box. It would have to
be infinitely thin, such as a line segment.

Note:  This can be checked "in real life" with a pencil whose length is as
close to your answer (given in the hidden answer as a reduced radical).

Or, it may be easier to tell/check if all of the dimensions of the rectangular
box and the alleged (length of the) pencil are multiplied, by say,
a factor of 5.

------------------------------------------------------------------------------------

#2974
The same is true for the rod.  It would have to be infinitely thin, too.

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Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi,

To reconsideryouranswer: The reasons for your solutions are fine. But these are mathematical problems!

To bobbym: The solution 2975 I get is 750 m[sup]3[/sup] or 750 000 000 cc.

The solution 2976 is perfect. Neat job!

#2977.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solution 2977 is correct. Brilliant!

#2978.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

reconsideryouranswer

Member

Registered: 2011-05-11

Posts: 171

Re: 10 second questions

Hi,

To reconsideryouranswer: The reasons for your solutions are fine.
But these are  >>> mathematical problems!  <<<

[/math]

They're *all* mathematical problems, so that isn't new information.
That doesn't change anything.  Not only is it a "mathematical
question," it is simultaneously a real-world question.
You simply admit you had a flawed question.  If you want a
proper mathematical answer to a mathematical problem,
then please word it with that in mind.

You avoid a problem with this, for example, by asking what is
the longest straight-line distance (line segment) inside of a
rectangular box with those dimensions.

Then the problem or question is clear/precise and unambiguous.

---------------------------------------------------------------------------------

Here is another one:

There are two rectangular boxes, each having dimensions of

If the two boxes touch each other in at least at one shared point,
then what is the longest possible straight-line distance in feet
spanning from the furthest section of one box to the furthest
section of the other box?

Last edited by reconsideryouranswer (2011-06-11 16:30:53)

---

Signature line:

I wish a had a more interesting signature line.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi,

To reconsideryouranswer : Your explanation is accepted and taken on record. Henceforth, I shall try to solve the problems on these lines.

To bobbym :  The solution 2978 is perfect. Excellent!

#2979. In a simultaneous throw of two dice, what is the probability of getting a total of 7?

#2980. What is the probability of getting a sum 9 from two throws of a dice?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solutions 2979 and 2980 are both correct. Neat job!

#2981. If the 9[sup]th[/sup] term of an Arithmetic Progression is zero, then what is the ratio of 29[sup]th[/sup] term to 19[sup]th[/sup] term?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solution 2891 is correct. Good work!

#2892. What is the value of

?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solution 2892 is correct. Well done!

#2893. If

, then what is the value of x?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solution 2893 is perfect. Excellent!

#2894. If the sum of the roots of the equation ax[sup]2[/sup] + 2x + 3a = 0 is equal to their product, then what is the value of a?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: 10 second questions

hi ganesh

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solution 2894 is correct. Well done!

#2895. Find the quadratic equation whose roots are the reciprocal of the roots of the equation x[sup]2[/sup] - 3x + 2 = 0.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solution 2895 is perfect. Well done!

#2896. The sum of the length, breadth, and depth of a cuboid is 19 cm and its diagonal is

cm. Find its surface area.

#2897. A swimming pool 9 m wide and 12 m long is 1 m deep on the shallow side and 4 m deep on the deeper side. Find its volume.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

#2898. If 2x + 3y = 34 and

, find the value of 5y + 7x.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: 10 second questions

Hi bobbym,

The solutions 2897 and 2898 are perfect. Brilliant work!

#2899. If 2x + 3y + z = 55, x + z - y = 4, and y - x + z = 12, what are the values of x, y, and z?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

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.