The price of an automobile decreased m percent between 2010 and 2011 and then increased n percent between 2011 and 2012. Was the price of the automobile lower in 2010 than in 2012?The price in 2010 - \(p\);

The price in 2011 - \(p*(1-\frac{m}{100})\);

The price in 2012 - \(p*(1-\frac{m}{100})*(1+\frac{n}{100})\);

Question: is \(p<p*(1-\frac{m}{100})*(1+\frac{n}{100})\)? --> is \(1<(1-\frac{m}{100})*(1+\frac{n}{100})\)? --> is \(100n-100m>mn\)?

(1) m < n. Not sufficient.

(2) mn < 100n – 100m. Directly answers the question. Sufficient.

Answer: B.

Identical question from OG to practice:

the-annual-rent-collected-by-a-corporation-from-a-certain-89184.html How we can say that Stat.1 is NOT sufficient even without plugging in values? I'm getting it clear by plugging values but what I'd like to know is there any faster way to determine the sufficiency of Stat.1 from the inequality?