Wmi 9B
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Nguyễn Hải MinhWmi 9B
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Nguyễn Hải MinhPast Paper
9B
◎Ten points each. Total 100 points. Choose the best answer from (A) – (D) .
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3＋ 5 3－ 5
1) Compute － .
2 2
(A) 2 (B) 1 (C) 5 (D) 2 5
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2) If a＝ 2 ＋1, find (a＋2)(a－2)＋a(4－a).
(A) 4 2 (B) 4 2 －4 (C) 2 2 ＋4 (D) 4 2 ＋4
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1 2 1 2
3) Compute 1＋1 ＋1 ＋2＋2 ＋2 ＋3＋……＋20.
3 3 3 3
2 1
(A) 610 (B) 609 (C) 609 (D) 609
3 3
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x －1 4 － y z －6
4) Suppose x≧0, y≧0, z≧0, and ＝ ＝ , find the maximum value of xy＋yz＋xz.
2 2 3
(A) 50 (B) 60 (C) 66 (D) 72
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1
5) As in the figure below, a frog starts from A and moves according to the pattern of A→B(step 1)
→C(step 2)→D→A→B→E→F→A→B→C……. Where will the frog be at step 999?
(A) A (B) F (C) B (D) D
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6) A, B, C, D, and E work on a project together. If A, B, C, and D work together, it can be done in 8
days. If B, C, D, and E work together, it can be done in 6 days. If A and E work together, it can be
done in 12 days. How many days does A need if he works on the project alone?
(A) 60 (B) 48 (C) 40 (D) 36
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2
7) If k is an integer that makes all the roots of the equation kx ＋(k＋1)x＋(k－1)＝0 integers, how
many such k's are there?
(A) 1 (B) 2 (C) 3 (D) 4
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8) There is a family with three children. If the chances of a boy or a girl being born are the same, what
is the probability that at least one of the three children is a boy?
1 3 7 2
(A) (B) (C) (D)
3 4 8 3
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2
9) Fill numbers 1～9 in the boxes below respectively (numbers 1, 2, and 4 are already filled in the
boxes). Each number can only be used once. If the sum of the three numbers on each side is the same,
find the minimum sum of A and B.
(A) 17 (B) 13 (C) 12 (D) 11
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10) Given a 4-digit number to form two 2-digit numbers with its first two digits and its last two digits
(the tens digit of a 2-digit number cannot be 0). If the square number of the sum of these two
2
2-digit numbers equals this 4-digit number, for example 3025, (30＋25) ＝3025, how many
other such 4-digit numbers are there that satisfy the conditions above?