Step-by-step explanation:
On the 8 branch, to the left is 2, and on the right is 4. On the left branch, and on the left, it is 2, and there is a 2 for the 6 branch.
Answer:
Step-by-step explanation:
2005 AMC 8 Problems/Problem 20
Problem
Alice and Bob play a game involving a circle whose circumference is divided by 12 equally-spaced points. The points are numbered clockwise, from 1 to 12. Both start on point 12. Alice moves clockwise and Bob, counterclockwise. In a turn of the game, Alice moves 5 points clockwise and Bob moves 9 points counterclockwise. The game ends when they stop on the same point. How many turns will this take?
$\textbf{(A)}\ 6\qquad\textbf{(B)}\ 8\qquad\textbf{(C)}\ 12\qquad\textbf{(D)}\ 14\qquad\textbf{(E)}\ 24$
Solution
Alice moves $5k$ steps and Bob moves $9k$ steps, where $k$ is the turn they are on. Alice and Bob coincide when the number of steps they move collectively, $14k$, is a multiple of $12$. Since this number must be a multiple of $12$, as stated in the previous sentence, $14$ has a factor $2$, $k$ must have a factor of $6$. The smallest number of turns that is a multiple of $6$ is $\boxed{\textbf{(A)}\ 6}$.
See Also
2005 AMC 8 (Problems • Answer Key • Resources)
Preceded by
Problem 19 Followed by
Problem 21
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All AJHSME/AMC 8 Problems and Solutions
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.
#1 first we need to solve for slope which is y2-y1/x2-x1
plug in the coordinates and get 1-6/5-(-2) which makes our slope -5/7
then use the equation for point slope form which is:
y-y1=m(x-x1)
then plug in one of the coordinates, I'll use (-2,6), now we have
y-6=-5/7(x+2)
now to make this slope intercept, we just have to solve
y-6=-5/7x-10/7
y=-5/7x+4 4/7
repeat all these steps for 2 and 3
#2: slope = -13/5
plug it in to point slope and get: y+8=-13/5(x-3)
slope intercept:
y+8= -13/5x + 39/5
y= -13/5x -1/5
#3: slope = 3/4
point slope form: y-2=3/4(x-3)
slope intercept: y-2=3/4x-9/4 --> y=3/4x-1/4
Answer:
3
Step-by-step explanation:
w= x
l= x-4
x(x-4) = 45
x^2-4x = 45
