2. On September 13, Mr. Zhang entered an oversold stock at the price of 4.8 yuan. The next day, the stock rose by 0.42 yuan, by what percentage? Is this percentage increasing or decreasing? Why?
0.42/4.8=0.0875, which is 8.75%. This percentage is the rise and fall, because the limit of the Shanghai and Shenzhen stock exchanges on the rise and fall of non-S and non-ST stocks is 10%.
3. At 3 pm on September 15, the cumulative increase of Mr. Zhang's stock has reached 15%. If he bought 20,000 shares, how much money has he made now?
4.80× 0.15× 20000 =14400 yuan
Now he has made a profit of 14400 yuan.
4. 17 September, around 1 in the afternoon, Mr. Zhang sold the stock in time and got 15000 yuan from the stock denomination. What is the share price at this time?
4.80+ 15000/20000 = 5.55 yuan
The share price at this time is 5.55 yuan.
The above calculation ignores the transaction cost.