2 A two-digit number, by exchanging its digits with the digits of ten, the new number is 54 larger than the original number, and the original two digits are-17-, -28- and -39-?
3 Choose 8 numbers from 1-9 and fill them in the following 8 O's, so that the equation holds.
[O/O *(O+O)]-(O * O+O-O)= 13 1
; [9/ 1*(8+7)]-(2*3+4-6)= 13 1
The product of 4 4 adjacent even numbers is a five-digit A838A (two A's represent the same number), so these four numbers are-12-,-14-,-16- and-18- respectively.
A tour group rented a car to travel, and each paid 40 yuan on average. Later, eight people were added, and the money paid by each person was 35 yuan. How much is the car rental fee? 2240 yuan (I can provide a solution if necessary).
6 Xiaoguang, Xiaoming, Xiao Qiang and Xiaohua took part in the math contest. The scores of the four people are different integers, with an average of 80 points. Xiaoguang scored the least, 6 points less than Xiao Ming; Xiaohua scored the highest, 8 points more than Xiao Qiang. How many points did Xiaohua get in the exam? At least 85 points (I can provide solutions if necessary).
7 Two shopping malls, A and B, buy the same kind of clothes. Shopping mall A bought five more sets than shopping mall B, but they were all sold out. Both shopping malls earned 400 yuan. If Mall A buys at the price of Mall B, it should earn 500 yuan. What was the original unit price of clothes sold in the mall? (Formula solution) 16 yuan (I can provide the solution if necessary).
Solution: The unit price of clothes sold in Mall B =(500-400)/5=20 yuan/set.
Shopping mall B clothing =400/20=20 sets.
Clothing in a shopping mall =20+5=25 sets.
Unit price of clothes sold in a shopping mall =400/25= 16 yuan/set.
(Plus points for all correct answers)