Its not a hard Mathematical question, it can be solved in few minutes, so did I. But I couldn't figure out proper equation and procedure to solve. could you help me out with it?
A father gave his son Rs 20 and asked him to get three things; books that cost Rs 5 each, notebooks that cost Re 1 each and pencils that costs 25p each. He also told him that he will be rewarded if total number of books, notebooks and pencils will be 20 too.
I would appreciate if you could post all procedure to work it out.

 You are at Room A which has 3 Switches
 Room B has 3 bulbs each connected to 3 switches in room A .


Now question is how would you identify which switch belongs to which bulb under the following condition


---- You are only allowed to go to room B once.

first press the first switch and leave it for 5 mins then turn off that switch and turn on another switch for 2 mins and switch off that one also now finally switch on the third one and enter in to the room.

the lighting bulb is the third one and remaining 2 is:

Touch the bulb,  the bulb which has high heat is 2nd switch  one and which has less heat is the first switch.

i think i m correct .

No Quiero,

Room # A: Say, Swiches 1, 2 ,& 3.

Room# B; Say, Bulbs B1,B2 & B3 that correspond to Switches 1, 2 & 3 respectively.

-  Go to Room A and turn on switches 1 & 2 (leave switch 3 turned off).

- After few minutes turn off switch 2

- Now go to Room# B. You will see one of the bulbs lighting ie. A1- that corresponds to Switch 1

- Now touch remaining two bulbs i.e. A2 and A3.

- You will find bulb# A2 hot, as the switch # 2 was momentarily switched on.

-  You will feel A3 cold, as the switch # 3 was never turned on. 

So easy

La la milayo.  My answer would have been

1. Turn on the one light for sometime and turn it off
2. Turn on the next light and go to the room
3. Touch the two lights which is not glowing. one which is hot corresponds to the switch which was on for some time. Cold one will be the one which was never switched.

Thanks no_quiero and khaobadi for ur effort..

Find the 6th Number?

1, 2, 6, 42, 1806, …..?

3263442

1, 2, 6, 42, 1806, 1180482

 

This one is simple the series is the number n multiplied by n+1

1, 1*2, 2*3, 6*7, 42*43, 1806*1807.............

I got another brain-teaser.

Dhan Bahadur has three sons and nine Cows. The first cow gives 11 Liters of milk every week. The second gives 22 L of milk, the third gives 33 L and so on till the ninth cow gives 99 L of milk. One day he finds out he has cancer and will die soon. So he dicides to distribute the cow to his sons such a way that each of them will get equal amount of milk every week from their cows. But he couldn't work the combination of the cows that needs to be given to each of his sons.. can you help??

answer will be published tomorrow.. More than one answer is possible...

  I got another brain-teaser.

Dhan Bahadur has three sons and nine Cows. The first cow gives 11 Liters of milk every week. The second gives 22 L of milk, the third gives 33 L and so on till the ninth cow gives 99 L of milk. One day he finds out he has cancer and will die soon. So he dicides to distribute the cow to his sons such a way that each of them will get equal amount of milk every week from their cows. But he couldn't work the combination of the cows that needs to be given to each of his sons.. can you help??

answer will be published tomorrow.. More than one answer is possible...

The answer could be :

First Son:       (1) 11 + (2) 22 + (3) 33 + (4) 44 +  (5) 55 = 165 ltrs (5 cows)

Second Son:  (6) 66 + (9) 99                                           = 165 ltrs (2 cows)

Third Son:      (7) 77 + (8) 88                                           = 165 ltrs (2 cows)

But this combination is quite unequitable because one of the sons has to feed 5 cows to get 165 ltrs of milk whereas other two sons can get the same amount of milk by feeding only two cows each.

Now the fair distribution would be:

First Son:         (1) 11 +(6) 66 + (8) 88 = 165 ltrs

Second Son:    (2) 22 + (4) 44 + (9) 99 = 165 ltrs

Third Son:       (3) 33 + (5) 55 + (7) 77 = 165 ltrs

Note: The numbers in parantheses indicate the ith number of cow, where i = 1, 2, 3...............,9.  

clap clap clap!! well done Simsim!!!