Difference between revisions of "2023 AMC 8 Problems/Problem 15"
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==Solution 1== | ==Solution 1== | ||
− | Note that Viswam walks at a constant speed <math>60</math> blocks per hour, as he takes <math>1</math> minute to walk each block. After walking <math>5</math> blocks, he has taken <math>5</math> minutes, and he has <math>5</math> minutes remaining, to walk <math>7</math> blocks. Therefore, he must walk at a speed of <math>7 \cdot 60 \div 5 = 84</math> blocks per hour to get to school on time, from the time he starts his detour. Since he normally walks <math>\frac{1}{2}</math> mile, which is equal to <math>10</math> blocks, <math>1</math> mile is equal to <math>20</math> blocks. Therefore, he must walk at <math>84 \div 20 = 4.2</math> mph from the time he starts his detour, to get to school on time, so the answer is <math>\boxed{\textbf{(B)}\ 4.2}</math>. | + | Note that Viswam walks at a constant speed of <math>60</math> blocks per hour, as he takes <math>1</math> minute to walk each block. After walking <math>5</math> blocks, he has taken <math>5</math> minutes, and he has <math>5</math> minutes remaining, to walk <math>7</math> blocks. Therefore, he must walk at a speed of <math>7 \cdot 60 \div 5 = 84</math> blocks per hour to get to school on time, from the time he starts his detour. Since he normally walks <math>\frac{1}{2}</math> mile, which is equal to <math>10</math> blocks, <math>1</math> mile is equal to <math>20</math> blocks. Therefore, he must walk at <math>84 \div 20 = 4.2</math> mph from the time he starts his detour, to get to school on time, so the answer is <math>\boxed{\textbf{(B)}\ 4.2}</math>. |
− | pianoboy (Edits by [[User:ILoveMath31415926535 | + | pianoboy (Edits by [[User:ILoveMath31415926535,ILoveMath31415926535 and apex304]] and MrThinker) |
==Solution 2== | ==Solution 2== |
Revision as of 12:05, 26 January 2023
Contents
[hide]Problem
Viswam walks half a mile to get to school each day. His route consists of city blocks of equal length and he takes minute to walk each block. Today, after walking blocks, Viswam discovers he has to make a detour, walking blocks of equal length instead of block to reach the next corner. From the time he starts his detour, at what speed, in mph, must he walk, in order to get to school at his usual time?
Solution 1
Note that Viswam walks at a constant speed of blocks per hour, as he takes minute to walk each block. After walking blocks, he has taken minutes, and he has minutes remaining, to walk blocks. Therefore, he must walk at a speed of blocks per hour to get to school on time, from the time he starts his detour. Since he normally walks mile, which is equal to blocks, mile is equal to blocks. Therefore, he must walk at mph from the time he starts his detour, to get to school on time, so the answer is .
pianoboy (Edits by User:ILoveMath31415926535,ILoveMath31415926535 and apex304 and MrThinker)
Solution 2
Viswam walks blocks, or half a mile, in minutes. Therefore, he walks at a rate of mph. From the time he takes his detour, he must travel blocks instead of . Our final equation is
Solution by ILoveMath31415926535
Animated Video Solution
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Video Solution by Magic Square
https://youtu.be/-N46BeEKaCQ?t=4153
See Also
2023 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by Problem 14 |
Followed by Problem 16 | |
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.