2014 AMC 10B Problem 5

Below is the professionally curated solution for Problem 5 of the 2014 AMC 10B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2014 AMC 10B solutions, or check the answer key.

All of the real AMC 8, AMC 10, AMC 12, and AIME problems in our complete solution collection are used with official legal permission of the Mathematical Association of America (MAA).

Concepts:ratio and proportionlinear equation

Difficulty rating: 1280

5.

Doug constructs a square window using 8 8 equal-size panes of glass, as shown. The ratio of the height to width for each pane is 5:2, 5 : 2 , and the borders around and between the panes are 2 2 inches wide. In inches, what is the side length of the square window? \t\t

 26 \ 26

 28 \ 28

 30 \ 30

 32 \ 32

 34 \ 34

Solution:

Let the smaller side of a pane be a distance of x.x.

Then, the side length is 52+4x.5\cdot 2 + 4x. Also, the other direction has pane lengths of 2.5x.2.5x.

This means the side length is 32+2(2.5x).3\cdot 2 + 2(2.5x) . We solve for xx as follows: 10+4x=6+5xx=4\begin{align*}10+4x &= 6+5x \\ x&= 4\end{align*}

Therefore, the side length is 10+44=26.10+4\cdot 4 = 26.

Thus, the correct answer is A .

Problem 5 in Other Years