2023 AMC 8 Problems/Problem 9

Problem

Malaika is skiing on a mountain. The graph below shows her elevation, in meters, above the base of the mountain as she skis along a trail. In total, how many seconds does she spend at an elevation between $4$ and $7$ meters?

$\textbf{(A)}\ 6 \qquad \textbf{(B)}\ 8 \qquad \textbf{(C)}\ 10 \qquad \textbf{(D)}\ 12 \qquad \textbf{(E)}\ 14$

Solution 1

The time intervals in which Malaika's elevation is between $4$ and $7$ meters are:

from the $2$ nd to the $4$ th seconds

from the $6$ th to the $10$ th seconds

from the $12$ th to the $14$ th seconds

In total, Malaika spends $(4-2) + (10-6) + (14-12) = \boxed{\textbf{(B)}\ 8}$ seconds at such elevation.

~apex304, MRENTHUSIASM

Solution 2

We count the number of seconds and get $\boxed{\textbf{(B)}\ 8}$

Solution by ILoveMath31415926535

Video Solution 1 by SpreadTheMathLove

https://www.youtube.com/watch?v=lfyg5ZMV0gg

Video Solution by Magic Square

https://youtu.be/-N46BeEKaCQ?t=4903

2023 AMC 8 (Problems • Answer Key • Resources)
Preceded by Problem 8	Followed by Problem 10
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25
All AJHSME/AMC 8 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.

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