Difference between revisions of "2015 AMC 8 Problems/Problem 3"

(Created page with "Jack and Jill are going swimming at a pool that is one mile from their house. They leave home simultaneously. Jill rides her bicycle to the pool at a constant speed of <math>1...")
 
m (Solution 2)
 
(23 intermediate revisions by 13 users not shown)
Line 1: Line 1:
 +
==Problem==
 +
 
Jack and Jill are going swimming at a pool that is one mile from their house. They leave home simultaneously. Jill rides her bicycle to the pool at a constant speed of <math>10</math> miles per hour. Jack walks to the pool at a constant speed of <math>4</math> miles per hour. How many minutes before Jack does Jill arrive?
 
Jack and Jill are going swimming at a pool that is one mile from their house. They leave home simultaneously. Jill rides her bicycle to the pool at a constant speed of <math>10</math> miles per hour. Jack walks to the pool at a constant speed of <math>4</math> miles per hour. How many minutes before Jack does Jill arrive?
  
 
<math>\textbf{(A) }5\qquad\textbf{(B) }6\qquad\textbf{(C) }8\qquad\textbf{(D) }9\qquad \textbf{(E) }10</math>
 
<math>\textbf{(A) }5\qquad\textbf{(B) }6\qquad\textbf{(C) }8\qquad\textbf{(D) }9\qquad \textbf{(E) }10</math>
 +
 +
==Solution==
 +
Using <math>d=rt</math>, we can set up an equation for when Jill arrives at the swimming pool:
 +
 +
<math>1=10t</math>
 +
 +
Solving for <math>t</math>, we get that Jill gets to the pool in <math>\frac{1}{10}</math> of an hour, which is <math>6</math> minutes.  Doing the same for Jack, we get that
 +
 +
Jack arrives at the pool in <math>\frac{1}{4}</math> of an hour, which in turn is <math>15</math> minutes.  Thus, Jill has to wait <math>15-6=\boxed{\textbf{(D)}~9}</math>
 +
 +
minutes for Jack to arrive at the pool.
 +
 +
==Solution 2==
 +
T=D/s
 +
Jill: (1/10)x60 because in minutes, is equal to 6 min
 +
Jack:(1/4)x60 is 15 minutes.
 +
15-6 is 9, so our answer is <math>15-6=\boxed{\textbf{(D)}~9}</math>  - TheNerdWhoIsNerdy.
 +
 +
==Video Solution (HOW TO THINK CRITICALLY!!!)==
 +
https://youtu.be/srGyMofBMsE
 +
 +
~Education, the Study of Everything
 +
 +
 +
==Video Solution==
 +
https://youtu.be/YvYq3iM4jP8
 +
 +
~savannahsolver
 +
 +
==See Also==
 +
 +
{{AMC8 box|year=2015|num-b=2|num-a=4}}
 +
{{MAA Notice}}

Latest revision as of 19:24, 15 September 2024

Problem

Jack and Jill are going swimming at a pool that is one mile from their house. They leave home simultaneously. Jill rides her bicycle to the pool at a constant speed of $10$ miles per hour. Jack walks to the pool at a constant speed of $4$ miles per hour. How many minutes before Jack does Jill arrive?

$\textbf{(A) }5\qquad\textbf{(B) }6\qquad\textbf{(C) }8\qquad\textbf{(D) }9\qquad \textbf{(E) }10$

Solution

Using $d=rt$, we can set up an equation for when Jill arrives at the swimming pool:

$1=10t$

Solving for $t$, we get that Jill gets to the pool in $\frac{1}{10}$ of an hour, which is $6$ minutes. Doing the same for Jack, we get that

Jack arrives at the pool in $\frac{1}{4}$ of an hour, which in turn is $15$ minutes. Thus, Jill has to wait $15-6=\boxed{\textbf{(D)}~9}$

minutes for Jack to arrive at the pool.

Solution 2

T=D/s Jill: (1/10)x60 because in minutes, is equal to 6 min Jack:(1/4)x60 is 15 minutes. 15-6 is 9, so our answer is $15-6=\boxed{\textbf{(D)}~9}$ - TheNerdWhoIsNerdy.

Video Solution (HOW TO THINK CRITICALLY!!!)

https://youtu.be/srGyMofBMsE

~Education, the Study of Everything


Video Solution

https://youtu.be/YvYq3iM4jP8

~savannahsolver

See Also

2015 AMC 8 (ProblemsAnswer KeyResources)
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 AJHSME/AMC 8 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png