Difference between revisions of "2017 AMC 10A Problems/Problem 4"

(Problem)
m
Line 5: Line 5:
 
==Solution==
 
==Solution==
 
Every <math>30</math> seconds <math>3-2</math> toys are put in the box, so after <math>27\cdot30seconds</math> there will be <math>27</math> toys in the box.  Mia's mom will then put <math>3</math> toys into to the box and we have our total amount of time to be <math>27\cdot30+30=840</math> seconds, which equals <math>14</math> minutes. <math>\boxed{(B) 14}</math>
 
Every <math>30</math> seconds <math>3-2</math> toys are put in the box, so after <math>27\cdot30seconds</math> there will be <math>27</math> toys in the box.  Mia's mom will then put <math>3</math> toys into to the box and we have our total amount of time to be <math>27\cdot30+30=840</math> seconds, which equals <math>14</math> minutes. <math>\boxed{(B) 14}</math>
 +
 +
==See Also==
 +
{{AMC10 box|year=2017|ab=A|num-b=3|num-a=5}}
 +
{{MAA Notice}}

Revision as of 15:38, 8 February 2017

Problem

Mia is “helping” her mom pick up $30$ toys that are strewn on the floor. Mia’s mom manages to put $3$ toys into the toy box every $30$ seconds, but each time immediately after those $30$ seconds have elapsed, Mia takes $2$ toys out of the box. How much time, in minutes, will it take Mia and her mom to put all $30$ toys into the box for the first time? $\textbf{(A)}\ 13.5\qquad\textbf{(B)}\ 14\qquad\textbf{(C)}\ 14.5\qquad\textbf{(D)}\ 15\qquad\textbf{(E)}\ 15.5$

Solution

Every $30$ seconds $3-2$ toys are put in the box, so after $27\cdot30seconds$ there will be $27$ toys in the box. Mia's mom will then put $3$ toys into to the box and we have our total amount of time to be $27\cdot30+30=840$ seconds, which equals $14$ minutes. $\boxed{(B) 14}$

See Also

2017 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
Problem 3
Followed by
Problem 5
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

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