Percent of a percent w/ one value and rate of change

[photopartner]

Hello - I'm trying to learn the method for this technique, which I think is getting a percent of a percent.

Problem: Unemployment dropped 30% from April's high to the current 10.2% in July. What is the April unemployment percent? thanks.

 

[Deleted member 4993]

Hello - I'm trying to learn the method for this technique, which I think is getting a percent of a percent.

Problem: Unemployment dropped 30% from April's high to the current 10.2% in July. What is the April unemployment percent? thanks.

Please show us what you have tried and exactly where you are stuck.

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Please share your work/thoughts about this problem.

 

[photopartner]

Hi - the problem has multiple choice answers so I can simply calculate the percent decrease by process of elimination with this formula:
(14.6%-10.2%)/14.6% = 30%

But without multiple choice (the answer being 14.6%), how do I determine the answer with only the rate of change (30%) and one value (10.2%)?

thanks.

 

[Deleted member 4993]

Hello - I'm trying to learn the method for this technique, which I think is getting a percent of a percent.

Problem: Unemployment dropped 30% from April's high to the current 10.2% in July. What is the April unemployment percent? thanks.

Assume that the unemployment rate of april was x% (= x/100)

Now it decreased by 30%. So

Unemployment rate in July = (1 - 0.3) * x = 0.7 * x

We know

Unemployment rate in July (= 10.2% =)10.2/100 = 0.102

So

0.7 *x = 0.102 \(\displaystyle \ \ \to \ \ \) x = 0.102/0.7 =?

finish it....

 

[photopartner]

Subhotosh - thanks so much for working through this problem step by step. That helped make it connect for me. The last part (current unemployment percent divided percent part of whole or .102/.7) was the lightbulb moment. I can't believe it's that simple. Thanks so much for your time.