## ValentinaT Group Title Help please? With steps? one year ago one year ago

1. ValentinaT Group Title

2. e.mccormick Group Title

How far did you get with this?

3. ValentinaT Group Title

Hold on a second please, I'm writing.

4. e.mccormick Group Title

Kk. Cause I do have a path to the answer...

5. ValentinaT Group Title

$\frac{ 72 }{ 2 } + \frac{ 72 }{ x } = \frac{ 72 }{ 1.5 }?$

6. e.mccormick Group Title

hmm... I can see where you got the 72/2 and 72/1.5.... but the 72/x makes no sense to me.

7. ValentinaT Group Title

Sorry, I was looking at the example in my book, and tried to model it like it.

8. e.mccormick Group Title

$$c_1 cpm=\frac{72}{2}$$ and $$c_2 cpm=?$$ Where cpm is Copies Per Minute $$1.5(c_1 cpm+c_2 cpm)=72$$

9. e.mccormick Group Title

Once you know the CPM for the old copier, you can find out how long it takes to make 72 copies.

10. ValentinaT Group Title

Sorry, I was writing this down.

11. e.mccormick Group Title

Your method might actually do that in one shot, don't know. You could run it both ways and see.

12. ValentinaT Group Title

How do I find the cpm for the old copier? $1.5(\frac{ 72 }{ 2 } + \frac{ 72 }{ x }) = 72$?

13. e.mccormick Group Title

You just need x. Not 72/x.

14. ValentinaT Group Title

Okay. $1.5(\frac{ 72 }{ 2 } + x) = 72$

15. ValentinaT Group Title

Can you give me a hint on what to do next?

16. e.mccormick Group Title

Move the 1.5 to the other side, do the dractions. They become nice numbers.

17. e.mccormick Group Title

fractions... oops. I was checking the other way. It would get a very bad number.

18. ValentinaT Group Title

Okay. $\frac{ 15 }{ 10 } (\frac{ 72 }{ 2 } + x) = 72$ End up with 12.

19. e.mccormick Group Title

My version of the work:$1.5\left(\frac{ 72 }{ 2 } + x\right) = 72 \\ \implies \frac{ 72 }{ 2 } + x = \frac{72}{1.5} \\ \implies 36 + x = 48 \\ \implies x = 48-36 \\ \implies x = 12$So 12 copies per minute. Then the time for 72 copies is $$\frac{72}{12}$$

20. ValentinaT Group Title

Okay, thank you.

21. e.mccormick Group Title

Yah, these and riverboat problems are all about finding what is added and what is multiplied. The true goal of word problems is trying to help you figure out how math works in real life rather than just in homework.

22. ValentinaT Group Title

Okay, 6 minutes.

23. e.mccormick Group Title

/cheer Yep. Really slow copier.

24. ValentinaT Group Title

Haha.