math troubles: Using scale on architectural drawing

[smileyfreak1538]

Hi everyone! I'm trying to get my weekend homework done but I had a few problems. I hope someone can help me!

On an architect's blueprint, 1 inch corresponds to 12 feet. If an exterior wall is 80 feet long, find out how long the blueprint measurement should be. Write answeres as a mixed number.

Also if you could explain how you got the answer that would be awesome!
Thanks Jamie

 

[jonboy]

Hi smileyfreak1538! I hope you've studied proportions.

That is a comparison of two ratios \(\displaystyle \,\frac{a}{b}\,\). Hence a proportion is:\(\displaystyle \L \;\frac{a}{b}\,=\,\frac{c}{d}\)

So since 1 in. corresponds to 12 ft. the ratio is \(\displaystyle \,\frac{1}{12}\,\).

Now we know the denominator for this part: "the exterior wall is 80 ft. long"

We'll call the unknown \(\displaystyle \,x\,\). Its ratio is \(\displaystyle \frac{x}{80}\).

So now we have our proportion:\(\displaystyle \L \;\frac{1}{12}\,=\,\frac{x}{80}\).

Solve for \(\displaystyle x\) by cross multiplication.

 

[Denis]

Re: math troubles

Hi everyone! I'm trying to get my weekend homework done but I had a few problems. I hope someone can help me!

Wow! We finally get a student who can write properly!
Keep that up, Jamie.