Math Is Fun Forum

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: 48,385

Re: 10 second questions

Hi bobbym,

The solutions #3152 and #3153 are correct. Excellent!

#3154. A tank 4 meter long, 2.5 meter wide, and 1.5 meter deep is dug in a field 31 meter long, and 10 meter wide. If the earth dug out is evenly spread out over the field, find the rise in level of the field.

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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: 48,385

Re: 10 second questions

Hi bobbym,

#3155. A rectangular carpet has an area of 60 square meters. If its diagonal and longer side together equals 5 times the shorter side, what is the length of the carpet?

---

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.

Denominator

Member

Registered: 2009-11-23

Posts: 220

Re: 10 second questions

Hello

Thanks

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Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Hi bobbym and Denominator,

The solution #3155 is correct. Good work!

#3156. A rectangle has width a and length b. If the width is decreased by 20% and the length is increased by 10%, then what is the area of the new rectangle in percentage compared to ab?

#3157. If the length and breadth of a rectangular plot be increased by 50% and 20% respectively, then how many times would its area be increased?

---

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.

Denominator

Member

Registered: 2009-11-23

Posts: 220

Re: 10 second questions

Thanks

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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: 48,385

Re: 10 second questions

Hi Denominator and anonimnystefy,

The solutions #3156 and #3157 are perfect. Brilliant!

#3158. If the length and breadth of a rectangular room are each increased by 1 meter, then the area of floor is increased by 21 square meters. If the length is increased by 1 meter and the breadth is dereased by 1 meter, then the area is decreased by 5 square meters. Find the perimeter of the floor.

---

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.

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: 48,385

Re: 10 second questions

Hi bobbym and anonimnystefy,

The solution #3158 is correct. Good work!

#3159. A river 1.5 meter deep and 36 meters wide is flowing at the rate of 3.5 kilometers per hour. Find the amount of water that runs into the sea per minute (in cubic meters).

---

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: 48,385

Re: 10 second questions

Hi bobbym,

The solution #3150 is correct. Excellent!

#3151. How many words can be formed from the letters of the word 'DIRECTOR' so that the vowels are always together?

---

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.

Denominator

Member

Registered: 2009-11-23

Posts: 220

Re: 10 second questions

Oh, I don't know much about combinations but:

Last edited by Denominator (2011-08-18 07:17:01)

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Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Hi bobbym and Denominator,

I get the same solution #3151 as both of you. Excellent!

#3152. The diameter of the driving wheel of a bus is 140 cm. How many revolutions per minute must the wheel make in order to keep a speed of 66 km/hour?

#3153. A wheel makes 1000 revolutions in covering a distance of 88 kilometers. Find the radius of the wheel.

(For #3152 and #3153, use

)

---

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.

Denominator

Member

Registered: 2009-11-23

Posts: 220

Re: 10 second questions

Hi ganesh!

---

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Hi bobbym and Denominator,

The solutions #3152 and #3153 are both correct. Brilliant!
The solution #3153 is correct, Denominator. Well done!
(The solution #3152 is

)

#3154. Find the ratio of the areas of the incircle and circumcircle of a square.

---

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

EDIT:so this is what that new topic is about.

Last edited by anonimnystefy (2011-08-19 03:37:04)

---

“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: 48,385

Re: 10 second questions

Hi bobbym and anonimnystefy,

The solution #3154 is perfect. Well done!

#3155. If a boat goes 7 km upstream in 42 minutes and the speed of the stream is 3 km/hour, then what is the speed of the boat in still water?

#3156. A man's speed with the current is 15 km/hour and the speed of the current is 2.5 km/hour. What is the man's speed against the current?

---

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.