Riddles Options

[vivekpm]

ayoooo Vivekah..
am getting slightly scared of u now..
u r an evil mathematician !!
ye lo ..since you love maths so much
5. A car has a journey of 78 miles to make.
The first half of the journey is uphill, and the second half downhill.
He averages 30 miles an hour to the top of the hill.
How fast must he go down the hill to average 60 miles per hour?

Though I would very much love to be one, but I am not a mathematician . At one point of time, I used to play a lot with numbers. But you seem to have a treasure of puzzles, that keep puzzling me. All good riddles

Now this one, is there a finite answer to this one? My calculations tell me that to make 60 miles/hour, he should cover the distance in 78 minutes (obviously) and by the time car reaches on the top of the hill (at 30 miles/hour), it would have taken exactly that much time (to cover 39 miles uphill at 30 miles/.hour).

So I think 60 miles/hour is impossible unless car can travel infinitely fast downhill or have a free fall with infinite acceleration, without being influenced by gravity of course. I better shut up here because I know Physics is not my cup of tea and have seen your inputs on this subject on other thread

Cheers,

[Mandrake]

VIVEK(PM), YOU ARE NOT TOO GOOD...




YOU ARE BRILLIANTTTTTT!!!!!

Main toh fida ho gaya aapke super-sharp intellect pe

Why don't you start a thread to teach us some more secrets of maths?
(Meri toh life ban jaayegi HF peh seekhoonga aur baahar public ko impression maaroonga )

Vivek, I am serious. Can you pls teach us some maths-fun?

Pls...

[shivani]

mmmm Vivek : ) since you are on roll.. another one...

6. A man is on top of a 20 storied building, when he sees a bear approaching him. To avoid getting killed by bear, he jumps from the building.. (better way of dying maybe ). A window cleaner observes that this falling guy took 2 seconds while crossing 18th floor which was 2.2 meters high. So the question is.. What is the color of bear ?

[divz]

mmmm Vivek : ) since you are on roll.. another one...

6. A man is on top of a 20 storied building, when he sees a bear approaching him. To avoid getting killed by bear, he jumps from the building.. (better way of dying maybe ). A window cleaner observes that this falling guy took 2 seconds while crossing 18th floor which was 2.2 meters high. So the question is.. What is the color of bear ?

Vivek u r damn brilliant in maths.......

oye shivani ye kya Q hai... mere ko laga ki koi mathematical hi hoga par yahan to tumne pata nahi kya pooch liya.... vaise India me to black bear hi milte hain...

[shivani]

well.. mathematical Question hi hai Divvy and maine kab bola ki ye indi ki baat hai.. think beyond .. think colors

[vivekpm]

VIVEK(PM), YOU ARE NOT TOO GOOD...




YOU ARE BRILLIANTTTTTT!!!!! 

Main toh fida ho gaya aapke super-sharp intellect pe

Why don't you start a thread to teach us some more secrets of maths?
(Meri toh life ban jaayegi HF peh seekhoonga aur baahar public ko impression maaroonga )

Vivek, I am serious. Can you pls teach us some maths-fun?

Pls...

Mandrake, aap khamokha itni taarif kar rahe ho . Aap jaise multi-talented personality ke aage mai kuch bhi nahin .

I am simply amazed to see your knowledge on all the various topics that are being discussed on other threads. Then there are many others on HF who have far deeper knowledge of various subjects ranging from Physics to Spirituality. I just wonder, "Jeevan Ki Aapa Dhaapi Main" aap sab kaise itna kuch sheekh lete hai?

On the other hand, I am just a novice, even in Mathematics. I just sometimes think about and play with numbers for fun. I really am not confident that I can teach anyone Mathematics. Someday, I will try though.

Cheers,

[vivekpm]

mmmm Vivek : ) since you are on roll.. another one...

6. A man is on top of a 20 storied building, when he sees a bear approaching him. To avoid getting killed by bear, he jumps from the building.. (better way of dying maybe ). A window cleaner observes that this falling guy took 2 seconds while crossing 18th floor which was 2.2 meters high. So the question is.. What is the color of bear ?

This reminds me of another problem, a man walks 10 Kms South, then 10 Kms East and then walks 10 Kms North. He finds himself at same position from where he started. But during this time, there is a bear waiting for him there. What is the colour of the bear?

The answer to this one was "White" as if you walk touwards south, then east and then north and reach the same point, you are at North Pole (theoritically). So I guess the answer to your question is also white? Only this time it should be something to do with acceleration due to gravity being more (or less?) at poles. As I said I am not too good with Physics and so it would be great if you/someone can explain?

Cheers,

[shivani]

well you answered it again Vivekahh
It is gravity !!
The approx value of G as per 2.2 mts and 2 secs comes close to 10 .. which is higher than normal.
And since G is more at poles.. it has to be a polar bear.. white : )

too tired to find another one now.. get ready for tomorrow though .. I got a few on probability

[vivekpm]

well you answered it again Vivekahh
It is gravity !!
The approx value of G as per 2.2 mts and 2 secs comes close to 10 .. which is higher than normal.
And since G is more at poles.. it has to be a polar bear.. white : )

too tired to find another one now.. get ready for tomorrow though .. I got a few on probability

I am running away!!!

Aaj office mai aadha din puzzles hi solve kiye hai. Ab kal to thoda kaam kar loon. Upar se probability, I better find some place to hide now.

Seems you have a great source for all these puzzles. Keep posting...

Cheers,

[visuja]

Good ones, Shivani .. kahaan se copy-paste kar rahi ho !

Both the polar bear ones and the speed of car one were good. I would never have figured out the polar bear for sure.. car waala shaayad.. but saw the solution before began thinking on it.. too lazy

The doors one... BRILLIANT !! ..still to understand how the perfect squares ka funda ties in to the whole problem... though
Seriously Vivek, I second Mandrake's request ..... u seem to love numbers, and would be great if you could introduce us (resisting to use teach ) to some of the interesting 'games' with numbers.

Oh me got the rope one right !! yipppppeeeee !

[divz]

shiv.. kahan ho .. more riddles please......... i too got tht rope one correct.. while the door riddle was far beyond my comprehension..

well still the square no is a night mare for me.. could get it thoroughly... Vivek yaar fir se samjhao jara....

[vivekpm]

shiv.. kahan ho .. more riddles please......... i too got tht rope one correct.. while the  door riddle was far beyond my comprehension..

well still the square no is a night mare for me.. could get it thoroughly... Vivek yaar fir se samjhao jara....

Ok Divyanjali... let me try. Maine kaha tha naa, I am not good at teaching people

1. If you take any number, it will have at least two divisors, 1 and the number itself.
2. Assume that the number is not a perfect square, for simplicity take an example of 12.
3. Such a number, which is not a perfect square, will always have divisors in pairs.
4. For example, 12 = 3*4. 12 = 2*6. So this makes 3,4 and 2,6 as divisors of 12 along with 1 and 12 (as explained in step 1).
5. Note how all the divisors of a number which is not a perfect square can only occur in pairs.
6. Now take example of a perfect square, say 64.
7. Divisors for 64 will be 1 and 64 (as explained in step 1 above).
8. Apart from this, 64 = 2*32, 64=4*16, 64=8*8.
9. Notice that 2,32 is one pair and 4, 16 is one pair but 8 which is the root of 64 cannot occur in pair.
10. So this way, a perfect square will always have odd number of divisors.

Hope this makes it clear. Let me know if it needs to be more simpler .

Cheers,

[Mandrake]

Monsieur Vivekulus, vous etes tres amazant!!!

I think this name will do till we come up with a better one

[vivekpm]

Monsieur Vivekulus, vous avez tres amazant!!!

JaadugarJi... What does this mean ??? Monsieur is Mr. in French? My linguistic capabilities are limited to Eng,Hin,Mar and Guj

Cheers,

[divz]

shiv.. kahan ho .. more riddles please......... i too got tht rope one correct.. while the  door riddle was far beyond my comprehension..

well still the square no is a night mare for me.. could get it thoroughly... Vivek yaar fir se samjhao jara....

Ok Divyanjali... let me try. Maine kaha tha naa, I am not good at teaching people

1. If you take any number, it will have at least two divisors, 1 and the number itself.
2. Assume that the number is not a perfect square, for simplicity take an example of 12.
3. Such a number, which is not a perfect square, will always have divisors in pairs.
4. For example, 12 = 3*4. 12 = 2*6. So this makes 3,4 and 2,6 as divisors of 12 along with 1 and 12 (as explained in step 1).
5. Note how all the divisors of a number which is not a perfect square can only occur in pairs.
6. Now take example of a perfect square, say 64.
7. Divisors for 64 will be 1 and 64 (as explained in step 1 above).
8. Apart from this, 64 = 2*32, 64=4*16, 64=8*8.
9. Notice that 2,32 is one pair and 4, 16 is one pair but 8 which is the root of 64 cannot occur in pair.
10. So this way, a perfect square will always have odd number of divisors.

Hope this makes it clear. Let me know if it needs to be more simpler .

Cheers,

ya got it.. actually i wanted to ask how u applied this square no concept to the door problem.. but now its clear.... completely clear......

Mandrake.. french nahi aati..hindi ya angrezi me likho