Math Is Fun Forum

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.

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: 10 second questions

Hi ganesh & bobbym;

---

igloo myrtilles fourmis

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,762

Re: 10 second questions

Hi bobbym and John E. Franklin,

The solution 2903 is

. Well done, bobbym!

#2904. Evaluate :

.

#2905. Evaluate :

.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solutions 2904 and 2905 are correct. Excellent!

#2906. The length of a rectangle is decreased by r%, and the breadth is increased by (r + 5)%. Find r, if the area of the rectangle is unaltered.

#2907. The length of a rectangle is increased by 60%. By what percent would the width have to be decreased so as to maintain the same area?

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solutions 2906 and 2907 I get are 20 (The value of r) and 37.5% respectively. Please verify.

#2908. What is the percentage increase in the area of a rectangle, if each of its sides is increased by 20%?

---

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;

I am making a big mess on 2906 and 2907. If you have a method that works please post it.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solution 2908 is perfect. Well done!

#2909. What is the square root of 1048576?

---

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;

Thanks for your solution.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solution 2909 is correct. Well done!

#2910. Find the least number exactly divisible by 12, 15, 20, and 27.

#2911. Find the least number which when divided by 6, 7, 8, 9, and 12 leaves the same remainder 1 in each case.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solution 2910 is correct. Neat job!
The solution 2911 is 505, not 504.

#2912. How many prime numbers are less than 50?

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solution 2912 is correct. Well done!

#2913. Find the volume and surface area of a cuboid 16 m long, 14 m broad, and 7 m high.

#2914. Find the length of the longest pole that can be placed in a room 12 m long, 8 m broad, and 9 m high.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solutions 2913 and 2914 are correct. Brilliant!

#2915. The volume of a wall, 5 times as high as it is broad and 8 times as long as it is high, is 12.8 cubic meters. Find the breadth of the wall.

#2916. Find the number of bricks, each measuring 24 cm x 12 cm x 8 cm, required to construct a wall 24 m long, 8 m high, and 60 cm thick, if 10% of the wall is filled with mortar.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solutions 2915 and 2916 are perfect. Brilliant work!

#2917. Water flows into a tank 200 m x 150 m through a rectangular pipe 1.5 m x  1.25 m @ 20 kilometers per hour. In what time (in minutes) would the water rise by 2 meters?

#2918. The dimensions of an open box are 50 cm, 40 cm, and 23 cm. Its thickness is 3 cm. If 1 cubic cm of metal used in the box weighs 0.5 grams, find the weight of the box.

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solution 2917 is correct. Neat job!

Regarding 2918, I get 8.04 kilograms.

#2920. By how much does

exceed

---

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;

Yes, I think you are right. It looks like I forgot that the 3 cms is removed twice ( both sides ). Good question!

---

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: 46,762

Re: 10 second questions

Hi bobbym,

The solution 2920 is perfect. Good work!

#2921. The diagonal of a cube is

cm. Find its volume and surface area.

#2922. The surface area of a cube is 1734 square cm.  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: 46,762

Re: 10 second questions

Hi bobbym,

The solutions 2921 and 2922 are correct. Neat job!

#2923. A rectangular block 6 cm x 12 cm x 15 cm is cut into an exact number of equal cubes. Find the least possible number of cubes.

---

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.