Math Is Fun Forum

NullRoot

Member

Registered: 2007-11-19

Posts: 162

Re: 10 second questions

It's a sad day for a mathematician when he believes 3³ = 9...

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Trillian: Five to one against and falling. Four to one against and falling… Three to one, two, one. Probability factor of one to one. We have normality. I repeat, we have normality. Anything you still can’t cope with is therefore your own problem.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

Well done, mathsyperson!
Neat work!

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#616. What is the sum to first ten terms of the series:-
1,4,7,10,......

#617. What is the sum to first five terms of the series:-
1,3,9,27....

#618. What is 10% of 20% of 30% of 100?

#619. What is the curved surface area of a cylinder of radius 7 cms and length 100 cms? (Use pi=22/7)

#620. What is the area of a triangle whose sides are 2 centimeters, 4 centimeters, and 4 centimeters?

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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.

NullRoot

Member

Registered: 2007-11-19

Posts: 162

Re: 10 second questions

Last edited by NullRoot (2008-01-31 00:22:49)

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Trillian: Five to one against and falling. Four to one against and falling… Three to one, two, one. Probability factor of one to one. We have normality. I repeat, we have normality. Anything you still can’t cope with is therefore your own problem.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

Answers #616 to #620.
Excellent, NullRoot! All correct!

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#621. What is the difference between simple interest and compound interest on a sum of $1000 at 10% per annum, compounded annually, for a period of 3 years?

#622. If a product is sold for $1300 at 50% loss, what is the cost of the product?

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#623. How many zeros does a vigintillion contain?

#624. What percent of 15 is 0.0015?

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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.

JohnnyReinB

Member

Registered: 2007-10-08

Posts: 453

Re: 10 second questions

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"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"

Nisi Quam Primum, Nequequam

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

Well done, JohnnyReinB!
Answers #621 to #624, all correct!
Keep it up!

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#625. What is the sum of the three cube roots of unity?

#626. What is the value of a single discount equal to successive discounts of 20% and 30%?

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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.

JohnnyReinB

Member

Registered: 2007-10-08

Posts: 453

Re: 10 second questions

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"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"

Nisi Quam Primum, Nequequam

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

No, JohnnyReinB, you aren't correct this time!

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#627. Use 8 eights and any number of mathematical operations and get a 1,000 exactly!

#628. Use 9 nines and any number of mathemitical operations and get a 1,000 exactly!

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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.

AshJones555

Member

Registered: 2006-05-15

Posts: 19

Re: 10 second questions

I'm not sure if this is right because im not sure if saying 8² counts as using one 8 or two but here's my attempt at #627 anyway:

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: 10 second questions

I'd say that 8² counts as using an 8 and a 2, and so isn't allowed (easily fixed by using 8x8 instead though).

I was thinking along the same lines as you, but couldn't quite get it to work. Your answer gave me the nudge I needed though:

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Why did the vector cross the road?
It wanted to be normal.

JohnnyReinB

Member

Registered: 2007-10-08

Posts: 453

Re: 10 second questions

You could do

. It's much simpler.

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"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"

Nisi Quam Primum, Nequequam

Kurre

Member

Registered: 2006-07-18

Posts: 280

Re: 10 second questions

Last edited by Kurre (2008-04-10 08:08:45)

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

mathsy, Johnny and kurre are all correct!
But I had the same answer as Johnny in my mind when I posted the question.

#629. What power of 2 is 16777216?

#630. How many times would you write the number 9 when you write the counting numbers from 1 to 1000?

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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.

AshJones555

Member

Registered: 2006-05-15

Posts: 19

Re: 10 second questions

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: 10 second questions

Ash, you've miscounted the amount of 9's in 990-998, meaning your final answer is nine short.
There's an easier way though:

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Why did the vector cross the road?
It wanted to be normal.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

Solution to #630:
mathsyperson, you are absolutely right!

#631. How many digits would the thousandth power of 2 contain?

#632. How many digits would the thousandth power of 3 contain?

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#633. What is the value of
3+6+9+12+........87+90?

#634. May 15, 2008 is a Thursday. What day of the week would May 15, 2009 be?

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#635. What is common between the numbers 625 and 2401?

#636. What is the volume of a sphere of radius 21 cm?

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#637. If a wheel contains 32 evenly spaced spokes, what is the angle in degrees between any two adjacent spokes?

#638. What is the temperature 3273 Kelvin in degrees Fahrenheit?

#639. How many numbers between 50 and 250 (both included) are divisible by the number 3?

#640. Which of the two is smaller in magnitude: The charge of an electron or radius of the nucleus of a Hydrogen atom (both in SI Units)?

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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.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,413

Re: 10 second questions

#641. Make a list of all the distinct prime factors of the number 384.

#642. How many subsets in all does the set {2,4,5,9} have?

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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.