WASHINGTON STATE MATHEMATICS COUNCIL 2000 MIDDLE SCHOOL MATH OLYMPIAD Session II ANSWERS: NOTE:   Take off half-credit if units were asked for in the question but not provided by the team. 5/6

Number Sense

1.    20

2.    11

3.    105

4.    1

5.    5/12

Measurement

1.    140

2.    25

3.    20%   (2 points for 19.722%)

4.    57,600

5.    4 inches

Geometric Sense

1.    91

2.    36

3.    8

4.    Any answer between 77,256 and 77,400 sq. ft. inclusive

5.    Any answer between 25.12 and 25.133 sq. cm. inclusive

Probability & Statistics

1.    1/2   or 5/10

2.    165   (Give 2 pts. for mean=84, mode=81)

3.    1/18 or 2/36

4.    97

5.    360

Algebraic Sense

1.    4

2.    10

3.       6*

W must be 5 or greater to cause the O in the hundreds column of the sum to be 7 (odd).   5 would not work, because it would cause the letter U and the letter F both to be worth 1.   8 would not work because T must be 8 to yield a sum of 17 with the carried 1 hundred.   W could not be 9 because it would cause U to be 9.   The numbers are as follows:   867 + 876 = 1724

4.    108   (Give 2 pts. For 27, 36, 45)

5.    152

Number Sense

1.    11

2.    6

3.    5/12

4.    9%

5.    24

Measurement

1.    96

2.    25

3.    57,600

4.    Saturday

5.    3.75 inches   or 3 3/4 inches

Geometric Sense

1.    8

2.    400% or 4 times   (Give 2 points for 4.)

3.    Any answer between 77,256 and 77,400   sq. ft. inclusive

4.    Any answer between 25.12 and 25.133 sq. cm. inclusive

5.    15 in.

Probability & Statistics

1.    246   (give 2 pts. for mean 84, mode 81, median 81)

2.    97

3.    360    (6x5x4x3x2)/2

4.   180    (5x4)/2  x   (3x2)/2 x   (4x3)/2

5.   1/29

Algebraic Sense

1.    4

2.    10

3.    36

4.    \$75

5.    12