12 March 2012

• 00:0200:02, 12 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 9
• 00:0200:02, 12 March 2012 diff hist +741 N 2004 AMC 8 Problems/Problem 9 Created page with "== Problem == The average of the five numbers in a list is <math>54</math>. The average of the first two numbers is <math>48</math>. What is the average of the last three numbers..."

11 March 2012

• 23:5323:53, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 8
• 23:5223:52, 11 March 2012 diff hist +368 N 2004 AMC 8 Problems/Problem 8 Created page with "== Problem == Find the number of two-digit positive integers whose digits total <math>7</math>. <math> \mathrm{(A)\ 6 }\qquad\mathrm{(B)\ 7 }\qquad\mathrm{(C)\ 8 }\qquad\mathrm{..."
• 23:4923:49, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 7
• 23:4823:48, 11 March 2012 diff hist +662 N 2004 AMC 8 Problems/Problem 7 Created page with "== Problem == An athlete's target heart rate, in beats per minute, is <math>80\%</math> of the theoretical maximum heart rate. The maximum heart rate is found by subtracting the ..."
• 23:4423:44, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 6
• 23:4223:42, 11 March 2012 diff hist +610 N 2004 AMC 8 Problems/Problem 6 Created page with "== Problem == After Sally takes <math>20</math> shots, she has made <math>55\%</math> of her shots. After she takes <math>5</math> more shots, she raises her percentage to <math>..."
• 23:3723:37, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 5
• 23:3623:36, 11 March 2012 diff hist +545 N 2004 AMC 8 Problems/Problem 5 Created page with "== Problem == The losing team of each game is eliminated from the tournament. If sixteen teams compete, how many games will be played to determine the winner? <math> \textbf{(A)..."
• 23:3223:32, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 4
• 23:3123:31, 11 March 2012 diff hist +476 N 2004 AMC 8 Problems/Problem 4 Created page with "== Problem == Ms. Hamilton’s eighth-grade class wants to participate in the annual three-person-team basketball tournament. Lance, Sally, Joy, and Fred are chosen for the team..."
• 23:2323:23, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 3
• 23:2223:22, 11 March 2012 diff hist +636 N 2004 AMC 8 Problems/Problem 3 Created page with "== Problem == Twelve friends met for dinner at Oscar's Overstuffed Oyster House, and each ordered one meal. The portions were so large, there was enough food for <math>18</math> ..."
• 22:2122:21, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 2
• 22:2022:20, 11 March 2012 diff hist +647 N 2004 AMC 8 Problems/Problem 2 Created page with "== Problem == How many different four-digit numbers can be formed be rearranging the four digits in <math>2004</math>? <math> \textbf{(A)}\ 4\qquad\textbf{(B)}\ 6\qquad\textbf{(..."
• 22:1122:11, 11 March 2012 diff hist +44 2004 AMC 8 Problems →Problem 1
• 22:0422:04, 11 March 2012 diff hist +480 N 2004 AMC 8 Problems/Problem 1 Created page with "== Problem == Ona map, a <math>12</math>-centimeter length represents <math>72</math> kilometers. How many kilometers does a <math>17</math>-centimeter length represent? <math> ..."
• 19:3619:36, 11 March 2012 diff hist +17 2010 AMC 8 Problems/Problem 11 →Solution
• 19:3319:33, 11 March 2012 diff hist +657 N 2010 AMC 8 Problems/Problem 11 Created page with "== Problem == The top of one tree is <math>16</math> feet higher than the top of another tree. The heights of the two trees are in the ratio <math>3:4</math>. In feet, how tall i..."
• 12:4312:43, 11 March 2012 diff hist +6 2010 AMC 8 Problems/Problem 19 →Solution
• 12:3912:39, 11 March 2012 diff hist +1,356 N 2010 AMC 8 Problems/Problem 19 Created page with "== Problem == The two circles pictured have the same center <math>C</math>. Chord <math>\overline{AD}</math> is tangent to the inner circle at <math>B</math>, <math>AC</math> is ..."
• 12:2512:25, 11 March 2012 diff hist −1 2003 AMC 8 Problems/Problem 21 No edit summary
• 12:2212:22, 11 March 2012 diff hist +346 2003 AMC 8 Problems/Problem 21 No edit summary
• 12:2112:21, 11 March 2012 diff hist +219 2003 AMC 8 Problems/Problem 21 No edit summary
• 11:3311:33, 11 March 2012 diff hist +136 2010 AMC 8 Problems/Problem 16 No edit summary
• 03:0003:00, 11 March 2012 diff hist +323 N 2010 AMC 8 Problems/Problem 16 Created page with "== Solution == Let the side length of the square be <math>s</math>, and let the radius of the circle be <math>r</math>. Thus we have <math>s^2=r^2\pi</math>. Dividing each side b..."
• 01:5001:50, 11 March 2012 diff hist +15 2003 AMC 8 Problems/Problem 21 No edit summary
• 01:3701:37, 11 March 2012 diff hist +585 N 2003 AMC 8 Problems/Problem 21 Created page with "Using the formula for the area of a trapezoid, we have <math>164=8(\frac{BC+AD}{2})</math>. Thus <math>BC+AD=41</math>. Drop perpendiculars from <math>B</math> to <math>AD</math>..."

25 February 2012

• 13:3413:34, 25 February 2012 diff hist −1 m 2012 AMC 12B Problems →Problem 12

20 June 2011

• 00:1900:19, 20 June 2011 diff hist +185 N 2000 AMC 8 Problems/Problem 16 Created page with "The length of the rectangle is 1000/25=40 meters. The perimeter equals 1000/10=100 meters. Perimeter is 2L+2W. Solving for W, we get 10 inches. The area is 40*10=400 square meter..."
• 00:1500:15, 20 June 2011 diff hist +260 N 2000 AMC 8 Problems/Problem 14 Created page with "Even powers of 19 have a units digit of 1, and odd powers of 19 have a units digit of 9. So, 19^19 has a units digit of 9. Powers of 99 have the exact same property, so 99^99 als..."
• 00:1000:10, 20 June 2011 diff hist +203 N 2000 AMC 8 Problems/Problem 10 Created page with "Shea grows 20%, so she was originally 60/1.2=50 inches tall which is a 10 inch increase. Since Ara grew half as much as Shea, Ara grew 5 inches therefore Ara is now 50+5=55 inche..."
• 00:0200:02, 20 June 2011 diff hist +162 N 1999 AMC 8 Problems/Problem 7 Created page with "The distance between the two exits is 160-40=120. 120*(3/4)=90, so the exit is 90 miles away from the third exit or at the 40+90=130 milepost, so the answer is E."

19 June 2011

• 22:4122:41, 19 June 2011 diff hist +189 N 1992 AJHSME Problems/Problem 8 Created page with "1500*0.1=150, so the store owner is <math>150 below profit. Therefore he needs to sell 150+100=</math>250 worth of pencils. Selling them at $0.25 each gives 250/0.25=1000 which i..."
• 22:0622:06, 19 June 2011 diff hist +216 N 1996 AJHSME Problems/Problem 3 Created page with "Obviously 1 is in the top left corner, 8 is in the top right corner, and 64 is in the bottom right corner. To find the bottom left corner, take away 7 from 64 which is 57. Adding..."
• 22:0022:00, 19 June 2011 diff hist +330 N 1996 AJHSME Problems/Problem 12 Created page with "Adding all of the numbers gives us (11)(12/2)=66. Since there are 11 numbers, the average is 66/11=6. We need to take away a number from the total sum and then divide the result ..."