Difference between revisions of "2015 AMC 10A Problems/Problem 1"

(Created page with "==Solution== Simply evaluating gives <math>\boxed{\textbf{(C)}frac15}</math>.")
 
(Video Solution)
 
(32 intermediate revisions by 13 users not shown)
Line 1: Line 1:
 +
{{duplicate|[[2015 AMC 12A Problems|2015 AMC 12A #1]] and [[2015 AMC 10A Problems|2015 AMC 10A #1]]}}
 +
==Problem==
 +
 +
What is the value of <math>(2^0-1+5^2-0)^{-1}\times5?</math>
 +
 +
<math> \textbf{(A)}\ -125\qquad\textbf{(B)}\ -120\qquad\textbf{(C)}\ \frac{1}{5}\qquad\textbf{(D)}\ \frac{5}{24}\qquad\textbf{(E)}\ 25</math>
 +
 
==Solution==
 
==Solution==
 +
<math>(2^0-1+5^2-0)^{-1}\times5 = (1-1+25-0)^{-1} \times 5 = 25^{-1} \times 5 = \frac{1}{25} \times 5 = \boxed{\textbf{(C) } \, \frac{1}{5}}</math>.
 +
 +
==Video Solution (CREATIVE THINKING)==
 +
https://youtu.be/yH4KLfe9p88
 +
 +
~Education, the Study of Everything
 +
 +
 +
 +
 +
==Video Solution==
 +
https://youtu.be/UdENmDoPGHU
 +
 +
~savannahsolver
  
Simply evaluating gives <math>\boxed{\textbf{(C)}frac15}</math>.
+
==See Also==
 +
{{AMC10 box|year=2015|ab=A|before=First Problem|num-a=2}}
 +
{{AMC12 box|year=2015|ab=A|before=First Problem|num-a=2}}
 +
{{MAA Notice}}

Latest revision as of 22:08, 26 June 2023

The following problem is from both the 2015 AMC 12A #1 and 2015 AMC 10A #1, so both problems redirect to this page.

Problem

What is the value of $(2^0-1+5^2-0)^{-1}\times5?$

$\textbf{(A)}\ -125\qquad\textbf{(B)}\ -120\qquad\textbf{(C)}\ \frac{1}{5}\qquad\textbf{(D)}\ \frac{5}{24}\qquad\textbf{(E)}\ 25$

Solution

$(2^0-1+5^2-0)^{-1}\times5 = (1-1+25-0)^{-1} \times 5 = 25^{-1} \times 5 = \frac{1}{25} \times 5 = \boxed{\textbf{(C) } \, \frac{1}{5}}$.

Video Solution (CREATIVE THINKING)

https://youtu.be/yH4KLfe9p88

~Education, the Study of Everything



Video Solution

https://youtu.be/UdENmDoPGHU

~savannahsolver

See Also

2015 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
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
2015 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
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 12 Problems and Solutions

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