For The Mathematically Inclined

For The Mathematically Inclined

Anil Saigal
08/11/2010

PROBLEM # 1

There are 9 balls. One of the balls is heavier than the rest, which all weigh the same. You have a balance. What is the least number of measurements it will take to find the heavier ball.

PROBLEM #2

There are 9 balls. One of the balls is heavier or lighter than the rest, which all weigh the same. You have a balance. What is the least number of measurements it will take to find the ball which is different from the rest.

----------------------------------------------------------------------------------------------------------

Please send your solutions to mr.asaigal@gmail.com.

Use Problem Solutions M-081910 as the subject line. Please include your full name in the text of the main message. Everyone with the right answer will be acknowledged in the next issue of Lokvani.

Please do not post your solution in Post Comments. No credit will be given for solutions not sent to anil@lokvani.com.

If you need clarification on any problem, please contact anil@lokvani.com.

-------------------------------------------------------------------------------------------------------------

Problems from 08/05/10

PROBLEM # 1

There is a clock that has a special way of telling the time. It does not have any hands or numbers on it, but it has a chimer.

If the time is 1 o'clock, it chimes once. If the time is 2 o'clock, it chimes twice, and so forth. The time gap between any two chimes is 4 seconds.

How many seconds would it take you to know the time, after the first chime is heard, if it is 6 o'clock?

SOLUTION

24 secs.

PROBLEM #2

"Dad, where had you been?" asked Ashok.

"I had been to the attic, my son," replied Dad. "And do you know what I saw there? There was a big web with 26 spiders and flies on it."

"How many spiders were there?" asked the boy with curiosity.

"Well, there were a total of 168 legs on the web," answered Dad with a smile. "Now you can find out how many spiders were there by yourself. Can't you?"

Can you help the little boy find out how many spiders were on the web in the attic?

SOLUTION

6 spiders.

Congratulations to Kishore Balsara, Akul Chennakesavan, Sophia Farooqui, Akshay Gowrishankar, Arun Lahori, Rajiv Ramaratnam, Ved Sirdeshmukh, Varun Tekur and Bharath Venkataraman, who were winners of the last set of puzzles.

You may also access this article through our web-site http://www.lokvani.com/