Difference between revisions of "2018 AMC 8 Problems/Problem 12"

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== Solution ==
 
== Solution ==
 
We see that every 35 minutes the clock passes, the watch passes 30 minutes. That means that the clock is <math>\frac{7}{6}</math> times faster than the watch, so when the car clock passes 7 hours, the watch has passed 6 hours, meaning that the time would be <math>\boxed{\textbf{(B) }6:00}</math>
 
We see that every 35 minutes the clock passes, the watch passes 30 minutes. That means that the clock is <math>\frac{7}{6}</math> times faster than the watch, so when the car clock passes 7 hours, the watch has passed 6 hours, meaning that the time would be <math>\boxed{\textbf{(B) }6:00}</math>
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Revision as of 18:28, 21 November 2018

Problem 12

The clock in Sri's car, which is not accurate, gains time at a constant rate. One day as he begins shopping he notes that his car clock and his watch (which is accurate) both say 12:00 noon. When he is done shopping, his watch says 12:30 and his car clock says 12:35. Later that day, Sri loses his watch. He looks at his car clock and it says 7:00. What is the actual time?

$\textbf{(A) }5:50\qquad\textbf{(B) }6:00\qquad\textbf{(C) }6:30\qquad\textbf{(D) }6:55\qquad \textbf{(E) }8:10$


Solution

We see that every 35 minutes the clock passes, the watch passes 30 minutes. That means that the clock is $\frac{7}{6}$ times faster than the watch, so when the car clock passes 7 hours, the watch has passed 6 hours, meaning that the time would be $\boxed{\textbf{(B) }6:00}$

2018 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
Problem 11
Followed by
Problem 13
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All AJHSME/AMC 8 Problems and Solutions