The price of a drug increased by 30% in 2008 and decreased by 70% in 2010. The price is 19.5 yuan

The price of a drug increased by 30% in 2008 and decreased by 70% in 2010. The price is 19.5 yuan

19.5/(1-70%)(1+30%)
=50

After the price of a drug increased by 30% in 2008 and decreased by 70% in 2010, the price is 19.5 yuan
+The answer!

19.5÷（1-70%）÷（1+30%）
＝19.5÷0.3÷1.3
＝50
A: the price of the drug was 50 yuan before the price increase in 2008

If the original price is a yuan, the price of a common medicine will be reduced by 40%, and then the price of the medicine will be ()

A-0.4A=0.6A

In order to solve the problem of people's difficulty in seeing a doctor, our government decided to reduce the price of drugs. After the price of a drug increased by 30% in 1999, it was reduced in 2001
70% to a yuan, then the price of the drug before the price increase is ()
A. One hundred a thirty nine percent
B. Thirty nine per cent
C. A (1-40%) yuan
D. 1-40% a yuan

Price after price increase = A / (1-70%)
Price before price increase = price after price increase / (1 + 30%)
Price before price increase = A / 39%
Choose a