Bunuel
In 2008, a certain factory produced 25% more widgets than it did in 2007. In 2009 the company’s production of widgets was 120% of its production in 2008. By approximately what percent would its production need to decrease the following year for the factory to produce the same number of widgets it did in 2007?
A. 33%
B. 45%
C. 50%
D. 64%
E. 67%
Useful property: percent increase and percent decrease are inversely proportional . . .
That means we can just flip a fraction. STEPS:
1) find the multiplier for the percent increase;
2) convert that to a fraction;
3) flip that fraction;
4) if we need a percent decrease, subtract that fraction from 1
That fraction's percent value is the percent decrease needed.
Let the factory's production = Q
1) Q increases twice: 2007-08 = 1.25, and 2008-09 = 1.2
To find Q's total percent increase, multiply the multipliers:
Total percent increase:
\(1.2 * 1.25 = 1.5\)2) Convert to a fraction:
\(1.5 = \frac{150}{100}=\frac{3}{2}\)3) Flip that fraction, to \(\frac{2}{3}\)
4) Subtract from 1*:
\((1-\frac{2}{3})=\frac{1}{3}\)PERCENT DECREASE NEEDED:
\(\frac{1}{3}\approx{33}\)%Answer A
*By flipping the fraction, we determine that the old Q is \(\frac{2}{3}\) of the current Q.
To get from (current) 1 Q to \(\frac{2}{3}\) Q (old), subtract \(\frac{1}{3}\) Q = 33%.
OR: \(\frac{2}{3}\) is 67%, which is 33% less than 100%