1 2007 coconino county math contest college bowl competitio n students, start your brain cells!

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1 2007 Coconino County Math Contest College Bowl Competition Students, start your brain cells!

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Page 1: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

1 2007 Coconino County

Math ContestCollege Bowl Competition

Students, start your brain cells!

Page 2: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

2

What is three more than twice seven?

[17]

Page 3: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

3Evaluate

:

[3]

52 −42

Page 4: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

4

Simplify:

[1/4]

15

+120

Page 5: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

5

Simplify:1-(3-(5-(7-9)))

[5]

Page 6: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

6

[10]

1

1 1

1 2 1

1 3 3 1

1 4 6 4 1

1 5 10 ?? 5 1

Page 7: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

7

What mathematician’s name is associated with

the array in the previous slide?

[Pascal]

Page 8: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

8

The first Annual Slug Race was held in 1998. When will the 20th one

be?

[2017]

Page 9: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

9

[11, 17]

0 1 2

1 3 5

2 5 8

3 7 11

4 9 14

5 ?? ??

Page 10: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

10

What are the prime factors of 330,000?

[2, 3, 5, 11]

Page 11: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

11

What number is three more than half of

itself?

[6]

Page 12: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

12

What number is three less than half of

itself?

[-6]

Page 13: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

13

Sam is two years older than his brother Jim. The sum of their ages is 30. When will the sum of their ages be

40?

[2012]

Page 14: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

14

[9]

1 3 5

15 17 7

13 11 ???

Page 15: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

15

If t = 4 and Q = 11, what is the value of

(Q-1)/(t+1)?

[2]

Page 16: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

16

George tells you that the average of 20

consecutive numbers (i.e. positive

integers) is 52800. What do you deduce?

[That George is a liar]

Page 17: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

17

“x@y” stands for x/(y-x). What, then, is

6@(4@2)?

[-3/4]

Page 18: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

18

Calculate:

[3]

10+12

32

+2

Page 19: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

19

The problem says, “The first number is 7 more than twice the second number.” If the first number is t, what is the second number?

[(t-7)/2]

Page 20: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

20

If I drive at 30 mph for 20 minutes, then 60

mph for 10 minutes, what is my average

speed?

[40 mph]

Page 21: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

21

Two numbers differ by 7 and their sum is 9.

What are they?

[1 and 8]

Page 22: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

22

Two numbers differ by 9 and their sum is 7.

What are they?

[8 and -1]

Page 23: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

23

[16]

14 36 25

26 15 34

35 24 ???

Page 24: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

24

Simplify:

[6/7]

1+12

1+34

Page 25: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

25

What is 110% of 90% of 300?

[297]

Page 26: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

26The sum of a number and

its reciprocal is smaller than the

number. How can that be?

[The number must be

negative]

Page 27: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

27

What is the area of circle of radius 1/π?

[1/π]

Page 28: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

28

[65]

23 25 27

43 45 47

63 ??? 67

Page 29: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

29

What value of x makes this possible?

[x = 65]

(x-5)º

xº(x-10)º

Page 30: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

30If a = 3, evaluate:

[17]

aa−1 +(a−1)a

Page 31: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

31

What is the next number in this sequence:

1, 0, 1, 1, 2, 3, 5, 8, . . . ?

[13]

Page 32: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

32

If , what is x?

[x = 9]

1+ x =2

Page 33: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

33

Simplify:

[1]

AB

+A + BB+ A

AB

+A + BB+ A

Page 34: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

34

10-(9-(8-(7-(6-5)))) = ?

[3]

Page 35: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

35

If A is always the average

of B and C, what is C when

A = 6 and B = 8?

[4]

Page 36: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

36 Simplify:

[3]

1+12

1−12

Page 37: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

37

Evaluate:

[4]

49− 9

Page 38: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

38

What is the next number in this sequence?48, 41, 34, 27, 20, . . . . .

[13]

Page 39: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

39

What is:| |3-8| - |2-11| |

?

[4]

Page 40: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

40

[16,22,29]

1 2 4

4 3 6

6 7 9

9 13 16

?? ?? ??

Page 41: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

41

What is the sum of these

nine numbers:

[99]

a=22 −12

b =32 −22

c=42 −32

d =52 −42

r =62 −52

s=72 −62

t =82 −72

x =92 −82

y =102 −92

Page 42: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

42 11 1 1

1 2 3 2 11 3 6 7 6 3

11 4 10 16 ? 16 10

4 1

[19]

Page 43: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

43See those four guys in line? I happen to know that each one has twice as much money as the

guy in front of him and a dollar more, as well. If the one in front

has $10 what does the guy in back have?

[$87]

Page 44: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

44

[301]

x y

1 4

2 7

3 10

4 13

... ...

100 ??

Page 45: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

45

Simplify:

[2/9]

15

+145

Page 46: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

46

R is less than T, and yet R2 is

greater than T2. How can that be?

[R is negative]

Page 47: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

47Evaluate

[2]

16=

Page 48: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

48

James was 26 when Suzie was born. How old will

Suzie be when he is three times as old as

she?

[13]

Page 49: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

49The rectangle is 4in x 9in and divided into

identical parts. What is the area of the

shaded region?

[16&1/2 sq. in.]

Page 50: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

50What do these shapes have in

common?

[They are all

parallelograms]

Page 51: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

51

Spell “ pair-uh-lllelll-uh-gram “

[parallelogram]

Page 52: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

52

The sum of four consecutive numbers is

50. What is the smallest of them?

[11]

Page 53: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

53 What do these six shapes all have

in common?

[Each one is a hexagon]

Page 54: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

54

What is the next number in this sequence:

44, 31, 13, 18, 5, 13, 8, …?

[5]

Page 55: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

55

20 feet per minute is how many inches per

second?

[4 in/sec]

Page 56: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

56

What is the smallest odd number k

such that is positive?

[5]

27

−1k

Page 57: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

57

The digram shows the seven clever pieces, often called

Tangrams, formed into a square. If the area of the square is 1, what is the

area of the smallest size of triangle, shown shaded?

[1/16]

Page 58: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

58

What is the next number in this sequence:

1, 2, 4, 7, 12, 20, 33, 54, 88, . . . ?

[143]

Page 59: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

59

1 + 2 + 3 + . . .+ 998 + 999+ 1000 = ?

[500500]

Page 60: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

60

N is the sum of four distinct odd numbers. What is the smallest N can

be?

[16]

Page 61: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

61 Which of these cannot be folded up to make a

cube?

[D]

A B

C

D

Page 62: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

62

[20]

18 2 13

6 11 16

9 ?? 4

Page 63: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

63

Kalkoola Middle School's student body is 60% 7th-graders and 40% 8-th graders. Half of the 7-th graders are bussed in, as are one-

fourth of the 8-th graders. What

proportion of the KMS kids walk to school?[60%]

Page 64: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

64Each of the triangles is

right and each of the

indicated legs has length 1. How long is the last hypotenuse

x?[2]1

1

1

1

X

Page 65: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

65

This is a non-convex pentagon.

It has two places where the lines cross. What is the greatest

possible number of crossings in

a pentagon?[5; in a star]

Page 66: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

66

What is the decimal form of the sum below?

[.526]

100061002105++

Page 67: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

67

How many square yards of carpet are needed to

carpet a rectangular room that measures 12 feet by

15 feet?

[20 sq. yds.]

Page 68: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

68

Simplify: (2i-1)(i-2)

[-5i]

Page 69: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

69

The points (2, 17), (5, 11) and (9,t) all lie

on the same line. What is the value of t?

[3]

Page 70: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

70 Consider all the points in the plane of the

form(t3+4Sin(t)-et,

t3+4Sin(t)-et +1).What is the shape of this set of points?

[The line y = x+1]

Page 71: 1 2007 Coconino County Math Contest College Bowl Competitio n Students, start your brain cells!

71 Three consecutive numbers add up to 3000. What are

they?

[999, 1000, 1001]