Art of Problem Solving

2013 AMC 8 Problems/Problem 11: Difference between revisions

Arpanliku (talk | contribs)
Arpanliku (talk | contribs)
Line 5: Line 5:


==Solution==
==Solution==
You have to find the hours spent on each day. The formula is d = r \times t, where d is distance, r is rate, and t is time.
You have to find the hours spent on each day. For people who do not know how to do this, here is a slower way to do it (you will be able to do quickly once you learn it):
 
On Monday, he spent 5 hours. So, 5x = 2 miles. x = <math>\frac{2}{5}</math> hours.


==See Also==
==See Also==
{{AMC8 box|year=2013|num-b=10|num-a=12}}
{{AMC8 box|year=2013|num-b=10|num-a=12}}
{{MAA Notice}}
{{MAA Notice}}

Revision as of 16:53, 27 November 2013

Problem

Ted's grandfather used his treadmill on 3 days this week. He went 2 miles each day. On Monday he jogged at a speed of 5 miles per hour. He walked at the rate of 3 miles per hour on Wednesday and at 4 miles per hour on Friday. If Grandfather had always walked at 4 miles per hour, he would have spent less time on the treadmill. How many minutes less?

$\textbf{(A)}\ 1 \qquad \textbf{(B)}\ 2 \qquad \textbf{(C)}\ 3 \qquad \textbf{(D)}\ 4 \qquad \textbf{(E)}\ 5$

Solution

You have to find the hours spent on each day. For people who do not know how to do this, here is a slower way to do it (you will be able to do quickly once you learn it):

On Monday, he spent 5 hours. So, 5x = 2 miles. x = $\frac{2}{5}$ hours.

See Also

2013 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
Problem 10
Followed by
Problem 12
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

These problems are copyrighted © by the Mathematical Association of America, as part of the American Mathematics Competitions. Error creating thumbnail: File missing