Math Is Fun Forum

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,423

Re: 10 second questions

Hi bobbym and phrontister,

bobbym : The #3387 is

phrontister : The solutions #3381, #3385, #3386, and #3387 are all correct. Outstanding!

(I made a solution in problem in the #3385; I stand corrected)

#3388. Three numbers are in the ratio 2:4:3. The sum of the largest and the smallest numbers is equal to the sum of the third number and 51. Find the largest number.

#3389. If A:B = 1:2, C:B = 4:3, and D:C = 6:5, then what is A : D?

---

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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,881

Re: 10 second questions

Hi ganesh,

---

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,423

Re: 10 second questions

Hi bobbym and phrontister,

The solutions #3388 and #3389 are perfect. Good work!

#3390. The average annual salary paid to all the workers in a factory was $5000. The average annual salary paid to the male and female workers were $5200 and $4200 respectively. Find the percentage of males and females employed by the factory.

#3391. The length and breadth of a room are in the ratio 3:2. Its area is 216 square meters. Find its perimeter.

---

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: 48,423

Re: 10 second questions

Hi bobbym,

The solutions #3390 and #3391 are perfect. Neat job!

#3392. A man rows a kilometer down the stream in 15 minutes and up the stream in 20 minutes. Find the velocity of the stream.

---

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: 48,423

Re: 10 second questions

Hi bobbym,

#3393. A, B, C can complete a work in 10 days, 15 days, and 12 days respectively. A and B together commence a work and they leave it after 3 days. What is the time taken by C to complete the remaining work?

#3394. Three persons A, B, C earn $170 per day; A and B together earn $120 per day; B and C together earn $130 per day. How much does B earn per day?

---

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: 48,423

Re: 10 second questions

Hi bobbym,

The solutions #3393 and #3394 are perfect. Brilliant!

#3395. A person sold his wristwatch for $119. The percentage of his profit was equal to the cost price. What was its cost price?

---

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: 48,423

Re: 10 second questions

Hi bobbym,

The solution #3395 is correct. Good work!

#3396. A pessenger train leaves a railway station 5 hours after a goods train leaves and overtakes the goods train in 5 hours. The passenger train runs at the speed of 60 kilometers per hour. What is the speed of the goods train?

#3397. 14 pumps working 8 hours a day can lift 2800 tons of water in 18 days. In how many days can 18 pumps working 9 hours a day lift 3600 tons of water?

---

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: 48,423

Re: 10 second questions

Hi bobbym,

The solutions #3396 and #3397 are correct. Impeccable!

#3398. The sum of four consecutive odd numbers is 56. Which is the last of them?

---

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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,881

Re: 10 second questions

Hi ganesh,

---

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,423

Re: 10 second questions

Hi bobbym and phrontister,

bobbym : The solution #3398 is correct. Excellent!

phrontister : The solutions #3390 and #3391 are correct. Excellent!
The solution #3392

.

#3399. The perimeter of the outer and inner circles of a race course are 1760 meters and 1540 meters respectively. Find the width of the race course. (Use

)

#3400. The cost of leveling a right triangular field whose hypotenuse is 130 meters and one side is 50 meters is $7500. What is the cost per square meter?

---

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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,881

Re: 10 second questions

Hi ganesh,

---

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi phrontister;

If you noticed I got the same answer you did. It is based on the premise that the boats velocity is constant ( 3 + 1 / 2 )mph in still water. This may not be correct.

---

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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,881

Re: 10 second questions

Hi Bobby,

True, but there must be some sort of premise in order to obtain a single, non-range answer.

In the real world, such a premise could only be applied to constants like a robot rower or Superman.

Last edited by phrontister (2011-11-18 12:12:22)

---

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi phrontister;

When I read ganesh's answer I really could not argue with his reasoning. I do not why my answer is wrong other than that it assumes a constant velocity.

---

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: 48,423

Re: 10 second questions

Hi bobbym and phrontister,

I am sorry I made a mistake twice in the solution #3392. The solution were perfectly in order. I stand corrected.

The solutions #3399 and #3400 are correct. Excellent!

#3401. $713 is shared among three persons A, B, and C in the ratio

. What is the share of B?

#3402. One number is one-fifth of the other number. Two-third of the smaller number added to one-ninth of the larger number is 22. Find the numbers.

---

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 about #3392.

---

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: 48,423

Re: 10 second questions

Hi bobbym,

The solution #3402 is correct. Good work!

#3403. $1800 is divided among A, B, and C such that A gets

times as much as B and B gets

times as much as C'share. What is the share 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.