By Anne Street
Try these question, the answers will be posted next week.
Q. 29 (Intermediate paper) and Q. 27 (Senior paper) IN 1998
We want to fill in the remaining squares in such a way that each of the numbers 1, 2, 3, 4, 5 and 6 appears in every row and every column. In how many ways can this be done? (Choose the correct answer.)
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ANSWERS |
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(A) 16 |
(B) 24 |
(C) 216 |
(D) 244 |
(E) 162 |
Q. 28 (Junior paper) Q. 26 (Intermediate paper) and Q. 20 (Senior paper) IN 1998
A 4x4 antimagic square is an arrangement in a square of the numbers from 1 to 16 so that the totals of each of the four rows and four columns and two diagonals are ten consecutive numbers in some order. The diagram shows an incomplete antimagic square. When it is completed, what number will replace the asterisk (*)? (Choose the correct answer.)
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ANSWERS |
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(A) 1 |
(B) 2 |
(C) 8 |
(D) 15 |
(E) 16 |
Q. 30 (Intermediate paper) and Q. 30 (Senior paper) IN 1992
It is proposed to colour the squares of a 4x4 board black and white, so that there are exactly two black squares and two white squares in each row or column. Two examples are shown here.
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In how many ways can this be done?
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ANSWERS |
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(A) 36 |
(B) 54 |
(C) 72 |
(D) 120 |
(E) 90 |