CODECHEF

The CodeChef.com Chal­lenge - your monthly dose of cod­ing puz­zles from In­dia's big­gest cod­ing con­test, now in print!

OpenSource For You - - DEVELOPERS -

Solve this month’s puz­zle, and you stand the chance of be­ing one of the three lucky peo­ple who could win a cash prize of Rs 1,000 each!

The Oc­to­ber edition’s puz­zle:

Here are the con­di­tions of the magic num­ber: 1. If the magic num­ber was a mul­ti­ple of 2, then it was a

num­ber from 50 through 59. 2. If it was not a mul­ti­ple of 3, then it was a num­ber

from 60 through 69. 3. If the magic num­ber was not a mul­ti­ple of 4, then it was a num­ber from 70 through 79. What was the magic num­ber?

The So­lu­tion:

1. Con­di­tion 1 elim­i­nates all mul­ti­ples of 2 ex­cept those from 50 to 59. There­fore, the num­bers elim­i­nated are 60, 62, 64, 66, 68, 70, 72, 74, 76 and 78. 2. Con­di­tion 2 in­di­cates that if the num­ber was not a mul­ti­ple of 3, it was a num­ber from 60 through 69. This elim­i­nates 50, 52, 53, 55, 56, 58, 59, 71, 73, 77 and 79. 3. Con­di­tion 3 in­di­cates that if the num­ber was not a mul­ti­ple of 4, then it was a num­ber from 70 through 79. This elim­i­nates 51, 54, 57, 61, 63, 65, 67 and 69. 4. The re­main­ing num­ber, 75, sat­is­fies all three con­di­tions. • It is not a mul­ti­ple of 2 and so it does not have to be a num­ber from 50 through 59. It is a mul­ti­ple of 3, and so it does not have to be a num­ber from 60 through 69.

• • It is not a mul­ti­ple of 4, and so it is, nec­es­sar­ily, a num­ber from 70 through 79. Hence, the an­swer is 75.

And the win­ners this month are:

• Saba Chaud­hary

• Paran­thaman

Here’s your CodeChef ‘Puz­zle of the Month’:

Our chef is fond of col­lect­ing in­ter­na­tional and In­dian postage stamps, and only he knows how many stamps he had. Once, when asked by one of his friends about the num­ber of stamps he owned, he replied with the fol­low­ing sen­tence:

“If I di­vide the stamps into two sets, viz., in­ter­na­tional and In­dian, then 5 times the dif­fer­ence be­tween the num­ber of stamps in each set equals half of the to­tal num­ber of stamps. Also, I’ve more num­ber of In­dian stamps com­pared to in­ter­na­tional ones. And half of the dif­fer­ence be­tween the squares of the num­ber of stamps in the In­dian and in­ter­na­tional set is 1620.”

Can you help the friend to find out how many in­ter­na­tional and In­dian stamps the chef has col­lected?

Look­ing for a lit­tle ex­tra cash?

Solve this month’s CodeChef Chal­lenge puz­zle and send in your an­swer to [email protected]­dia.com or [email protected] by Novem­ber 15, 2012. Three lucky win­ners get to win some awe­some prizes, both in cash and other mer­chan­dise! You can also par­tic­i­pate in the con­test by vis­it­ing the on­line space for the ar­ti­cle at https:// www.face­book.com/ Lin­uxForYou.