Difference between revisions of "2018 AMC 10A Problems/Problem 3"
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<math>\textbf{(A) }\text{January 2}\qquad\textbf{(B) }\text{January 12}\qquad\textbf{(C) }\text{January 22}\qquad\textbf{(D) }\text{February 11}\qquad\textbf{(E) }\text{February 12}</math> | <math>\textbf{(A) }\text{January 2}\qquad\textbf{(B) }\text{January 12}\qquad\textbf{(C) }\text{January 22}\qquad\textbf{(D) }\text{February 11}\qquad\textbf{(E) }\text{February 12}</math> | ||
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| + | ==Video Solution== | ||
| + | https://youtu.be/bPfLeXu9kx0 | ||
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| + | Education, the Study of Everything | ||
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== Solution 1 == | == Solution 1 == | ||
Revision as of 10:46, 29 November 2020
Problem
A unit of blood expires after 
seconds. Yasin donates a unit of blood at noon of January 1. On what day does his unit of blood expire?
Video Solution
Education, the Study of Everything
Solution 1
There are 
seconds that the blood has before expiring and there are 
seconds in a day. Dividing 
gives 
days. days after January 1 is 
.
Solution 2
The problem says there are 
seconds.
Convert seconds to minutes by dividing by 
: 
minutes.
Convert minutes to hours by again, dividing by : 
hours.
Convert hours to days by dividing by 
: 
days.
Now we need to count days after January 1. Since we start on Jan. 1, then we can't count that as a day itself. When we reach Jan. 31(The end of the month), we only have counted 30 days. 
. Count 
more days, resulting
~nosysnow and Max0815
Video Solution
~savannahsolver
See Also
| 2018 AMC 10A (Problems • Answer Key • Resources) | ||
| Preceded by Problem 2 |
Followed by Problem 4 | |
| 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 AMC 10 Problems and Solutions | ||
These problems are copyrighted © by the Mathematical Association of America, as part of the American Mathematics Competitions. 
