[讨论]9月math机经341题

nina23

341) PS:A test has 10 questions. The later question has 4 more points than the former. If a student who answered the test correctly the test, has 360 points in total. What are the points to third question?
参考答案：作者: My answer is 26
思路：


my answer is 44?  need conformation!

Zeros

10X+4*（1+9）*9/2=360

X=18

The third question = 18+2*4=26

nina23

got it,,I made a stupid mistake

3x!!