Other Percent Change Ques - Manhattan book Pg 99

[gunjan.kapil7]

Hi,

I am referring to the question from the example, Pg 99. Hammers & nails >> question: by what percent ratio hammers sold to nails sold decrease from first quarter to second quarter?

I understood, we calculated the ratio of first quarter and then of second quarter, however I did not understand the
If we now figure out the percent OF the Original that New represents, we can easily subtract...

I failed to understand the main part of the explanation:(

Please help

Thanks
Gunjan

[tim]

please post the full text of the problem so the answer we give you will help other students as well..

[gunjan.kapil7]

Hi Tim,

Thank you for the reply and sorry for the miss :)

The problem is the following:

In the first quarter of 2008, Harry's Hardware Store sold 300 hammers and 12,000 nails. In the second quarter of 2008, the store sold 375 hammers and 18,000 nails. By approximately what percent did the ratio of hammers sold to nails sold decrease from the first quarter to the second quarter.

A) 0.4%
B) 2.1%
C) 2.5%
D) 17%
E) 25%


I read the explanation again and understood that in order to find the percent change we "always" divide the change by the original and then multiply by 100. And from what I understood from "If we now figure out the percent OF the Original that New represents, we can easily subtract the answer from 100" is that we are finding New = x% of Original and by subtracting it from 100 we will find the decrease percent. Please correct me if my understanding is wrong or lacking anywhere.

One more question, if it would have been correct to find the percent decrease by New Ratio - Original Ratio/Original Ratio*100?? I understand it would be longer calculation. I want to be clear with the concept.

Thank you for taking out time and addressing the query.
Gunjan

[tim]

most of this is fine, but to find percent DECREASE you need to use (old-new)/old*100, not (new-old)/old*100..