Difference between revisions of "1997 PMWC Problems/Problem I13"
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== Problem == | == Problem == | ||
| − | A truck moved from A to B at a speed of 50 km/h and returns from B to A at 70 km/h. It traveled 3 rounds within 18 hours. What is the distance between A and B? | + | A truck moved from <math>A</math> to <math>B</math> at a speed of <math>50 \text{ km/h}</math> and returns from <math>B</math> to <math>A</math> at <math>70 \text{ km/h}</math>. It traveled <math>3</math> rounds within <math>18</math> hours. What is the distance between <math>A</math> and <math>B</math>? |
== Solution == | == Solution == | ||
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<math>\frac{12}{5}T_2=6\Rightarrow T_2=\frac{5}{2}</math> | <math>\frac{12}{5}T_2=6\Rightarrow T_2=\frac{5}{2}</math> | ||
| − | Therefore the distance from A to B is <math>\frac{5}{2} | + | Therefore the distance from A to B is <math>\frac{5}{2}\cdot70=\boxed{175}</math>. |
== See Also == | == See Also == | ||
Latest revision as of 12:13, 21 January 2019
Problem
A truck moved from 
to 
at a speed of 
and returns from to at 
. It traveled 
rounds within 
hours. What is the distance between and ?
Solution
The truck moved from A to B back and forth once in 18/3=6 hours. Let the time that it takes to go from A to B be 
, and let the time it takes to go from B to A be 
.
Therefore the distance from A to B is 
.
See Also
| 1997 PMWC (Problems) | ||
| Preceded by Problem I12 |
Followed by Problem I14 | |
| I: 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 T: 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 | ||
