Math Is Fun Forum

pi man

Member

Registered: 2006-07-06

Posts: 251

Re: 10 second questions

139. If

what is the value of n?

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Thanks pi man and kylekatarn!
I am happy posting the problems here, I do occasionally check for the problems which haven't been answered. Often, during the weekend. I shall post the solutions.
Thank again!

137. pi man, you are calculating assuming the interest is paid as compound interest, the question clearly says simple interest is paid.

139. I had the US Centillion in my mind, the reason being, in most places in the world, the US notation is followed, barring UK and some European nations, where a billion is a million million and so on.

143. How many odd numbers between 1 and 1000 are divisble by 7?

144. How many perfect powers exist between 1 and 1000? (perfect squares, perfect cubes, perfect fourth powers, etc.)

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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: 48,385

Re: 10 second questions

145. How many cubic inches make a cubic foot?

146. How many square yards make a square mile?

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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.

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: 10 second questions

Pi man, the US Centillion is a million multiplied by a thousand 99 times. Or if you prefer, a thousand multipled by a thousand 100 times.

You can derive that by thinking about what they do to get from a million to a billion, then to a trillion, and so on.

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

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Excellent, mathsyperson! I wonder if 10 seconds would have been sufficient! it took me a little longer!

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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: 48,385

Re: 10 second questions

147. What would be the successive sum of all the digits (that is, the sum of the repeatedly, until you get a single digit) of

148. What digit would

end in?

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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: 48,385

Re: 10 second questions

149. What is the lenght of the longest rod that can be placed inside a room 10m long, 10 m wide and 10 m high?

150. What is the probability of getting two black kings when two cards are drawn at random from a well shuffled pack of 52 cards, without replacement?

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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.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: 10 second questions

Last edited by JaneFairfax (2007-02-23 13:25:01)

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Excellent, JaneFairfax!
All your answers are 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: 48,385

Re: 10 second questions

151. An equilateral triangle is formed by joining the
middle points of the sides of a given equilateral triangle. A
third equilateral triangle is formed inside the second
equilateral triangle in the same way. If the process continues
indefinitely, then what is the sum of areas of all such triangles when
the side of the first triangle is 16 cm is?

152.  What is the sum of first 100 terms which are
common to both the progressions
17, 21, 25, ... and 16, 21, 26, ....?

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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.

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: 10 second questions

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

Dross

Member

Registered: 2006-08-24

Posts: 325

Re: 10 second questions

Last edited by Dross (2007-02-28 04:31:22)

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Bad speling makes me [sic]

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: 10 second questions

 

power man

Member

Registered: 2006-12-26

Posts: 160

Re: 10 second questions

true

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I hate people who hate people.
most people make mistakes, butt not me!
why     is     it     when     you     are     writing     something     important     you     run     out       of        spa

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Excellent, mathsyperson, dross, JaneFairfax and power man!!!

153. If both 11² and 33 are factors of the number

,
then what is the smallest possible value of 'a'?

154. When a number is divided by 36, it leaves a remainder of 19. What will be the remainder when the number is divided by 12?

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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.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: 10 second questions

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Outstanding, JaneFairfax!
:cool::cool:

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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.

Dross

Member

Registered: 2006-08-24

Posts: 325

Re: 10 second questions

 

Thank you for pointing that out Jane - I'll try not to be such a numpty in future!

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Bad speling makes me [sic]

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: 10 second questions

Don’t worry, it’s just a small mistake.

BTW, I’ll also appreciate it if people correct any mistakes they find in my posts, even my non-mathematical ones. I’ll be very grateful.

Last edited by JaneFairfax (2007-03-01 04:23:01)

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Janefairfax,
Thanks for the nice post!
You don't make mistakes in your posts, certainly not too often to be noticed,
and we'd be happy to correct you if you did!

155. If 20 men or 24 women or 40 boys can do a job in 12 days working for 8 hours a day, how many men working with 6 women and 2 boys take to do a job four times as big working for 5 hours a day for 12 days?

156. Two cogged wheels of which one has 32 cogs and other 54 cogs, work into each other. If the latter turns 80 times in three quarters of a minute, how often does the other turn in 8 seconds?

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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.

Dross

Member

Registered: 2006-08-24

Posts: 325

Re: 10 second questions

Last edited by Dross (2007-03-01 22:00:57)

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Bad speling makes me [sic]

quinton28

Member

Registered: 2007-03-04

Posts: 2

Re: 10 second questions

(3) How many times would you have to write the number 6 when you write from 1 to 100?

Ans is 20 times.

(4) A bus contains 23 men and 14 women. In the first stop after the start, 11 men board and 2 women do. In the next stop, 6 men board and 3 women do. In the next, 2 men alight and 2 women do, but also 2 men board the bus and 2 women do. The question is, how many places did the bust stop from the start to the destination? (You are granted 20 seconds for this, as a special case!)

lightning

Real Member

Registered: 2007-02-26

Posts: 2,060

Re: 10 second questions

Last edited by lightning (2007-03-05 08:20:37)

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Zappzter - New IM app! Unsure of which room to join? "ZNU" is made to help new users. c:

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: 10 second questions

Well done, Dross, quinton and lightning!

157. The time in a clock is 20 minute past 2. Find the angle between the hands of the clock.

158. At how many points between 10 O'clock and 11 O'clock are the minute hand and hour hand of a clock at an angle of 30 degrees to each other?

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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.

pi man

Member

Registered: 2006-07-06

Posts: 251

Re: 10 second questions