Difference between revisions of "2006 AMC 8"
| Line 55: | Line 55: | ||
'''Solutions''' | '''Solutions''' | ||
| − | 1. (D) Mindy's total was approximately <math>2+5+10= | + | 1. (D) Mindy's total was approximately <math>2+5+10=17.</math> |
2. (C) On the AMC 8 a student's score is the number of problems answered correctly. So Billy's score is 13. Because there is no penalty for guessing, if he wants to increase his score, he probably should fill in the last five answers. | 2. (C) On the AMC 8 a student's score is the number of problems answered correctly. So Billy's score is 13. Because there is no penalty for guessing, if he wants to increase his score, he probably should fill in the last five answers. | ||
| − | 3. (A) When Elisa started, she completed a lap in <math>\frac{25}{10}=2.5</math> minutes. Now she can complete a lap in <math>\frac{24}{12}=2</math> minutes. She has improved her lap time by <math>2.5-2=0.5 or \frac{1}{2}</math> minute. | + | 3. (A) When Elisa started, she completed a lap in <math>\frac{25}{10}=2.5</math> minutes. Now she can complete a lap in <math>\frac{24}{12}=2</math> minutes. She has improved her lap time by <math>2.5-2=0.5</math> or <math>\frac{1}{2}</math> minute. |
4. (B) Ignore the number of complete revolutions because they do not affect direction. One-fourth of the distance around the circle clockwise from west is north. Three-fourth of the distance counterclockwise around the circle from north is east. Chenille's spinner points east. | 4. (B) Ignore the number of complete revolutions because they do not affect direction. One-fourth of the distance around the circle clockwise from west is north. Three-fourth of the distance counterclockwise around the circle from north is east. Chenille's spinner points east. | ||
Revision as of 19:04, 28 January 2010
Problems
1. Mindy made three purchases for <dollar/>1.98, <dollar/>5.04, and <dollar/>9.89. What was her total, to the nearest dollar?
A) <dollar/>10
B) <dollar/>15
C) <dollar/>16
D) <dollar/>17
E) <dollar/>18
2. On the AMC 8 contest Billy answers 13 questions correctly, answers 7 incorrectly and doesn't answer the last 5. What is his score?
A) 1
B) 6
C) 13
D) 19
E) 26
3. Elisa swims laps in the pool. When she first started, she completed 10 laps in 25 minutes. Now she can finish 12 laps in 24 minutes. By how many minutes has she improved her lap time?
A) 
B) 
C) 1
D) 2
E) 3
4. Initially, a spinner points west. Chenille moves it clockwise 
revolutions and then counterclockwise 
revolutions. In what direction does the spinner point after the two moves?
A) north
B) east
C) south
D) west
E) northwest
Solutions
1. (D) Mindy's total was approximately 
2. (C) On the AMC 8 a student's score is the number of problems answered correctly. So Billy's score is 13. Because there is no penalty for guessing, if he wants to increase his score, he probably should fill in the last five answers.
3. (A) When Elisa started, she completed a lap in 
minutes. Now she can complete a lap in 
minutes. She has improved her lap time by 
or minute.
4. (B) Ignore the number of complete revolutions because they do not affect direction. One-fourth of the distance around the circle clockwise from west is north. Three-fourth of the distance counterclockwise around the circle from north is east. Chenille's spinner points east.
Copyright 2006, The Mathematical Association of America
