What is the ratio of the percent decrease from 4 to 1 to the percent

Question

What is the ratio of the percent decrease from 4 to 1 to the percent decrease from 10 to 7?

A. 1 : 1
B. 5 : 2
C. 4 : 3
D. 15 : 7
E. 25 : 1

DavidTutorexamPAL · Answer

We'll take a shortcut to calculation based on properties of ratios.
This is a Logical approach.

Ratios can be multiplied by a number without changing their value.
For example, a ratio of 4:1 is the same as 8:2 and 12:3.
To find the percent decrease from 4 to 1, we'll multiply by 25 to get 100 to 25.
We can SEE that this is a 75% decrease.
Similarly, multiplying 10 to 7 by 10 gives 100 to 70, a 30% decrease.
Therefore our answer is 75:30 = 15:6 = 5:2

(B) is our answer.

exc4libur · Answer

Percentage decrease:  1-\frac{After}{Before} , so  1-\frac{1}{4}=\frac{3}{4}=75 % and  1-\frac{7}{10}=\frac{3}{10}=30 %

Ratio:  \frac{3}{4}*\frac{10}{3}=\frac{10}{4}=\frac{5}{2}

(B) is the answer.

generis · Answer

Percent change (decrease or increase):

\frac{Old-New}{Old} * 100

From 4 to 1: 
 \frac{4-1}{4}=\frac{3}{4}= .75 * 100 = 75  percent

From 10 to 7:
 \frac{10-7}{10}=\frac{3}{10}=.30 * 100 = 30  percent

Ratio of first percent decrease to second percent decrease?
 \frac{75}{30}=\frac{15}{6} =\frac{5}{2}

Answer B

ScottTargetTestPrep · Answer

The percent change from 4 to 1 is:

(1 - 4)/4 x 100 = -300/4 = -150/2 = -75 percent

In other words, the percent decrease from 4 to 1 is 75 percent.

The percent change from 10 to 7 is:

(7 - 10)/10 x 100 = -300/10 = -150/5 = -30 percent

In other words, the percent decrease from 10 to 7 is 30 percent.

So the ratio is:

75/30 = 5/2

Answer: B

What is the ratio of the percent decrease from 4 to 1 to the percent

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What is the ratio of the percent decrease from 4 to 1 to the percent

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