2012美国数学竞赛AMC8.doc

2012 AMC 8 Problems
Problem 1
Rachelle uses  pounds of meat to make  hamburgers for her family. How many pounds of meat does she need to make hamburgers for a neighborhood ic?
Solution
Problem 2
In the country of East Westmore, statisticians estimate there is a baby born every  hours and a death every day. To the nearest hundred, how many people are added to the population of East Westmore each year?
Solution
Problem 3
On February 13  listed the length of daylight as 10 hours and 24 minutes, the sunrise was , and the sunset as . The length of daylight and sunrise were correct, but the sunset was wrong. When did the sun really set?
Solution
Problem 4
Peter's family ordered a 12-slice pizza for dinner. Peter ate one slice and shared another slice equally with his brother Paul. What fraction of the pizza did Peter eat?
Solution
Problem 5
In the diagram, all angles are right angles and the lengths of the sides are given in centimeters. Note the diagram is not drawn to scale. What is ,  in centimeters?
Solution
Problem 6
A rectangular photograph is placed in a frame that forms a border two inches wide on all sides of the photograph. The photograph measures 8 inches high and 10 inches wide. What is the area of the border, in square inches?
Solution
Problem 7
Isabella must take four 100-point tests in her math class. Her goal is to achieve an average grade of 95 on