You are here:

Puzzle Solving/Need Missing Numbers

Advertisement

Expert: Surajit Basu - 3/3/2008


Question
Put the digits 1 through 9, each used exactly once, into the circles so that the total of numbers in each line up, down, across and diagonally is the same, equals 15. Center number is in place.
?------?------6

?------?------?

?------3------?

Answer
A------B------6

C------D------E

X------3------Y

where can 9 be: not at A and B
where can 9 be: not at D and X, not at E and Y
so, it must be at C!

A+X = 6
So, X is 1/2/4/5
So, Y is ????.... clearly, X can't be 1 or 2.  So it must be 4 or 5

Go on like this, and you can find the magic square

2 7 6
9 5 1
4 3 8  

Puzzle Solving

All Answers

Answers by Expert:

Ask Experts

Volunteer

Surajit Basu

Expertise

I can answer questions which are mathematical, logical, or wordplay related. I am not good at highly creative problems, or riddles.

Experience

I regularly do puzzles, and help out friends, teenagers. I read books written by Martin Gardener. I love the puzzles and Easter eggs in Douglas Hofstadter's Godel, Escher, Bach: an enternal golden braid.

Publications
A few examples of my writing: http://surajitbasu.sulekha.com/blog/post/2006/04/the-journey-down-the-number-line.htm

Education/Credentials
B. Tech. ( Computer Science), IIT Kanpur, India MBA ( Post-Graduate Diploma in Business Management), (Finance, Systems), IIM Calcutta, India

©2012 About.com, a part of The New York Times Company. All rights reserved.